Kessler, C. (1993). International Scientific Cooperation, Consolidated report of activities, 1987 - 90.
Chicago-viite (17. p.)Kessler, C. International Scientific Cooperation, Consolidated Report of Activities, 1987 - 90. 1993.
MLA-viite (9. p.)Kessler, C. International Scientific Cooperation, Consolidated Report of Activities, 1987 - 90. 1993.
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