Gaya APA
Strevens, P., Inc., E, L, S. (1970).
English 901 a basic course programmed workbook 6 .
:
collier macmillan.
Gaya MLA
Strevens, Peter., Inc., English, Language, Services,.
"English 901 a basic course programmed workbook 6".
:
collier macmillan,
1970.
Text.