APA (7th ed.) Zitazioa
Egan, G. (1990). The skilled helper: A systematic approach to effective helping (4th ed.). Brooks / Cole.
Chicago Style (17th ed.) Zitazioa
Egan, Gerard. The Skilled Helper: A Systematic Approach to Effective Helping. 4th ed. California: Brooks / Cole, 1990.
MLA (9th ed.) Zitazioa
Egan, Gerard. The Skilled Helper: A Systematic Approach to Effective Helping. 4th ed. Brooks / Cole, 1990.
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