Ley, W. (1969). Events in space. New York: David McKay Company.
Trích dẫn kiểu ChicagoLey, Willy. Events in Space. New York: David McKay Company, 1969.
MLA citiranjeLey, Willy. Events in Space. New York: David McKay Company, 1969.
Opozorilo: Ti citati niso vedno 100% točni.