APA
Federation International Des Geometres, . (1990). XIX congress...Helsinki, June 10-19 1990: (Volume 10: supplementary volume of papers). Helsinki: FIG.
Chicago
Federation International Des Geometres, . 1990. XIX congress...Helsinki, June 10-19 1990: (Volume 10: supplementary volume of papers). Helsinki: FIG.
Harvard
Federation International Des Geometres, . (1990). XIX congress...Helsinki, June 10-19 1990: (Volume 10: supplementary volume of papers). Helsinki: FIG.
MLA
Federation International Des Geometres, . XIX congress...Helsinki, June 10-19 1990: (Volume 10: supplementary volume of papers). Helsinki: FIG. 1990.