Petry, N. M. (2011). Contingency management: What it is and why psychiatrists should want to use it. Royal College of Psychiatrists.
Dyfyniad Arddull ChicagoPetry, Nancy M. Contingency Management: What It Is and Why Psychiatrists Should Want To use It. Royal College of Psychiatrists, 2011.
Dyfyniad MLAPetry, Nancy M. Contingency Management: What It Is and Why Psychiatrists Should Want To use It. Royal College of Psychiatrists, 2011.
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