Gaya APA
Krueger, R, A. (1994).
Focus Groups Second Edition A Practical Guide for Applied Research (Second Edition).
The United States of America:
Sage Publications, Inc.
Gaya MLA
Krueger, Richard, A.
"Focus Groups Second Edition A Practical Guide for Applied Research".
Second Edition
The United States of America:
Sage Publications, Inc,
1994.
Text.