Gaya APA
Len, E., Yue, P. (1989).
Secondary vocabulary guide and practice .
Jakarta:
Preston Corporation (PTE)LTD-Binarupa.
Gaya MLA
Len, Evelyn., Yue, P.S..
"Secondary vocabulary guide and practice".
Jakarta:
Preston Corporation (PTE)LTD-Binarupa,
1989.
Text.