Sometimes an issue concentrates on a theme: for instance no.20 (Summer 1999) was on 'Conserving Russia's Forests', and no.38 (Winter/Spring 2005) focussed on the Russian Far East, particularly the salmon and other fish. RCN also produces a separate series on an occasional basis - 'Biodiversity Briefings from Northern Eurasia' - on specific topics, for example 'Russia's Endangered Seas', 'Kurile Islands'.