Introduction. In the context of methodological problems of bibliometrics, we consider the concept of the object of bibliometrics, viz. a document. In regard with the author’s view that the document is also an integral component of  the objects of scientometrics and informetrics, the share of this component being very significant, it seems important to attempt to review some of the evolution that the concept of a “document” has undergone since the dictionary definition of 1975, as the perception of the document as the object of bibliometrics did not incorporate the changes that the concept of a document has undergone irrespectively of its application to “metric” research.

Materials and methods. Analytical interpretation of scientific literature, international and national standards, as well as dictionary articles related to this problem. Based on the above interpretation, an attempt to review the evolution of the term “document” has been made.

Results. The article traces some of the evolution of the concept of “document” since the dictionary definition of 1975 up to the definition of the international standard of 2017 and the paper by Yu. N. Stolyarov of 2018. Currently, any material object that can be used to obtain the information a person needs may be considered as a document.

Discussion and conclusion. This interpretation of the concept of a document, as well as a number of its  predecessors, can be fruitful for a possible reconsideration of the concepts of the objects of bibliometrics,  scientometrics and informetrics.  

This article examines the system structure of Russian scholarly journal publishers. Bibliometric indicators, composition of authors and some features of editorial and publishing policy by different groups of publishers are analyzed. Proposals are presented on changing the editorial policy and introducing publishing services in order to promote Russian journals and improve their quality. 

The article deals with some new functions of DOI CrossRef system. Based on current database of more than 100 million of records containing DOIs and advanced sets of metadata new important functions of DOIs emerged. DOI is now widely used for discovery and accounting of publications’ mentions on the Internet by altmetric services and  CrossRef DOI Event Data. DOI CrossRef is also served as a basis for Unpaywall sevice which defines open access status of publications. Analyzed are typical problems of Russian publications preventing correct discovery of open access evidence by Unpaywall: missing DOIs, incomplete metadata registered with CrossRef and on publications web pages on the Internet, mistakes in DOIs.

Introduction. The COVID-19 pandemic is a global challenge but at the same time it creates a unique situation for the advancement of science, scholarly communication and open access (OA). We studied impact of the  pandemic and self-isolation on bibliometric indicators: the number and structure of publications in terms of  fields of research and OA models.

Materials and methods. The study employs original keyword searches and services of WoS CC database and InCites platfom of Clarivate Analytics. It studies the dataset of WoS CC and the COVID-publications retrieved with the keyword searches.

Results and discussion. In 2020, we see a dramatic increase in the overall number of COVID-publications and a two-time increase in the number of publications in Social Sciences.
The structure of the 2020 publications in terms of OA models indicate the 36 % of WoS CC articles and 87 % of COVID articles in OA. The OA journal articles in a single copy make 20 % of WoS CC publications, the OA  articles in multiple copies on the journal platform and in repositories make 60 % of COVID-publications.
In 2006, the OA repositories were mainly populated through self-archiving of paywall journal articles, whereas in 2020, the OA journals make the main self-archiving channel. They comprise, respectively, 92 % and  97 % of the input from the WoS CC and COVID datasets.
The structure of COVID publications in hybrid and paywall journals has been modified: in 2020, 38 % of articles in those journals were published in hybrid OA. In 2018, that number was 12 %.
The proportion of “paywall” articles moved to repositories after the embargo period is low compared to the  possibilities for self-archiving provided by publishers.

Conclusion. The pandemic of the novel coronavirus changed the bibliometric indicators of COVID publications: the number and structure of the datasets broken by fields of research and OA models. In the next study, we analyse citation impact and usage of COVID-publications.

Introduction. The COVID-19 pandemic creates a unique situation for the advancement of science, scholarly communication and open access (OA). We analyzed the impact of the pandemic on citation metrics and use of scholarly resources.

Materials and methods. The study employs original keyword searches and services of WoS CC database and  InCites platform of Clarivate Analytics. It studies citation impact of publications in the datasets of WoS CC,  Clinical Medicine and COVID-publications retrieved with the keyword searches. 
We studied OA reference groups in WoS CC classification represented by two subsets of publications with the  different number of available copies: Single and Multy. 

Results and discussion. Citation Impact of COVID-publications in OA reference groups exceeds by 5–10 times  Citation Impact of publications in Clinical Medicine and WoS CC. In 2020, the percent of Single and Multy publications varies around 30 % and 70 % in different reference groups. Due to additional citations collected in  OA repositories, the Citation Impact of COVID-publications in the Multy subset is 2–7 times higher than that in the Single subset. Repository copies of Multy publications of DOAJ, Bronze, Hybrid reference groups, collect, respectively, 85 %, 56 % и 85 % of citations in Multy subset. The Multy subsets of DOAJ, Bronze, Hybrid  reference groups make, respectively, the 76 %, 91 %, 80 % input in average Citation Impact of these groups. The citation patterns of publications of the WoS CC and Clinical Medicine datasets are similar but differ from the citation pattern of COVID-publications.
Our study confirmed research hypothesis on increase in use of scholarly resources upon pandemic COVID-19 and self-isolation on the example of resources of OA repositories. The number of visits of repositories in May 2020 exceeds by 2 times the number of visits in May 2019.

Conclusion. The pandemic of novel coronavirus resulted in the 10-time increase in Citation Impact of COVID  publications as compared with Citation Impact of publications in other fields of research. Citation Impact of the OA COVID-publications in different reference groups is determined by the articles available in OA repositories and depends by their relative share. This can be a reason of different results of studies Open Access Citation Advantage.

As a result of the development of the electronic environment, new actors appear in the scientific communication system, including repositories, mega-journals, and open peer review platforms, all of which operate in accordance with the open science paradigm. At the same time, the results of the work of scientists are still being assessed by traditional databases and scientometric services based mostly on the citation counts, which  is often irrelevant for the new projects due to non-compliance with formal criteria of such services. This article discusses the requirements of the Web of Science, Russian Science Citation Index, Scopus, and the Higher Attestation  Commission (VAK) for the sources of scientific information, and analyzes 25 projects for compliance with these requirements. It was revealed that some of the new projects do not meet the criteria due to the lack of traditional markers of the scientific publication. Based on the results obtained, a number of recommendations were formulated that will allow to adjust the requirements to reflect the new realities.