This paper evaluates the importance of jointly conducted research versus national, when neighbouring countries are trying
to study a topic of their mutual interest. The chosen topic was the shared ocean or lake basin. The number of non-mutual and
mutual articles in the period 1999–2008 for seven pairs of neighbouring countries was analysed by extracting published articles
and citations from the Web of Science database. It was found that mutual articles have generally better visibility than the
non-mutual articles, valid even for large and developed countries. Also, the percentage of self-citations in the mutual articles
is much lower than in the non-mutual ones. However, the citations of the non-mutual articles are influenced by the development
of the country or, in some cases, by the development of the countries in which researchers from a certain country are presently
working (this applies strongly to the Eastern Europe countries).