Gaya APA
Tull, D, S., Hawkins, D, I. (1980).
Marketing Research : Measurement and Method A Text with Cases (2nd. Ed).
United States of America:
Macmillan.
Gaya MLA
Tull, Donald, S., Hawkins, Del, I..
"Marketing Research : Measurement and Method A Text with Cases".
2nd. Ed
United States of America:
Macmillan,
1980.
Text.