Gaya APA
XVI International congress of surveyors, Montreux, 9-18 August 1981. (1981).
[s.l]:
International Federation of Surveyor.
Gaya MLA
XVI International congress of surveyors, Montreux, 9-18 August 1981.
.
[s.l]:
International Federation of Surveyor,
1981.
Text.