Goel, B. S. (1990). Marketing research (2 Edition.).
Chicago Style aipamenaGoel, B S. Marketing Research. 2 Edition. Pragati Prakashan, Meerut, 1990.
MLA aipamenaGoel, B S. Marketing Research. 2 Edition. 1990.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.