APA (7th ed.) Zitazioa
Collins, G. R. (1995). How to be a people helper. Tyndale House Publishers.
Chicago Style (17th ed.) Zitazioa
Collins, Gary R. How to Be a People Helper. Illinois: Tyndale House Publishers, 1995.
MLA (9th ed.) Zitazioa
Collins, Gary R. How to Be a People Helper. Tyndale House Publishers, 1995.
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