APA

International Geological Congress, Armstrong J. E., . (19). International Geological Congress, twenty-fourth session, Canada 1972. Ottawa: .

Chicago

International Geological Congress, Armstrong John E, . 19. International Geological Congress, twenty-fourth session, Canada 1972. Ottawa: .

Harvard

International Geological Congress, Armstrong J. E., . (19). International Geological Congress, twenty-fourth session, Canada 1972. Ottawa: .

MLA

International Geological Congress, Armstrong John E, . International Geological Congress, twenty-fourth session, Canada 1972. Ottawa: . 19.