Cummings, J. L., & Thomas, J. (2000). The value of psychological treatment: The collected papers of Nicholas A. Cummings. Zeig, Tucker & Co..
Lua i Stíl Chicago (17ú heag.)Cummings, Janet L., agus J.Lawrence Thomas. The Value of Psychological Treatment: The Collected Papers of Nicholas A. Cummings. Phoenix: Zeig, Tucker & Co., 2000.
Lua MLA (9ú heag.)Cummings, Janet L., agus J.Lawrence Thomas. The Value of Psychological Treatment: The Collected Papers of Nicholas A. Cummings. Zeig, Tucker & Co., 2000.
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