APA

International congr. of pure and applied chemistry (31 ; Sofia ; 1987), . (1987). 31st international congress of pure and applied chemistry, July 13-18, 1987, Sofia, Bulgaria. Sofia: Publishing House of the Bulgarian Academy of Sciences.

Chicago

International congr. of pure and applied chemistry (31 ; Sofia ; 1987), . 1987. 31st international congress of pure and applied chemistry, July 13-18, 1987, Sofia, Bulgaria. Sofia: Publishing House of the Bulgarian Academy of Sciences.

Harvard

International congr. of pure and applied chemistry (31 ; Sofia ; 1987), . (1987). 31st international congress of pure and applied chemistry, July 13-18, 1987, Sofia, Bulgaria. Sofia: Publishing House of the Bulgarian Academy of Sciences.

MLA

International congr. of pure and applied chemistry (31 ; Sofia ; 1987), . 31st international congress of pure and applied chemistry, July 13-18, 1987, Sofia, Bulgaria. Sofia: Publishing House of the Bulgarian Academy of Sciences. 1987.