Dat was 1968.

MLA

Martens, Ludo, and Kris Merckx. Dat Was 1968. Berchem: EPO, 1978.

APA

Martens, L., & Merckx, K. (1978). Dat was 1968. Berchem: EPO.

Chicago

Martens, Ludo, and Kris Merckx. Dat Was 1968. Berchem: EPO, 1978.