Gaya APA

Speert, J, L. (1967). Surveying and Mapping, Vol. XXVII, No. 4 December 1967 . : IPC Business Press Ltd..

Gaya MLA

Speert, Julius, L.. "Surveying and Mapping, Vol. XXVII, No. 4 December 1967". : IPC Business Press Ltd., 1967. Text.