Kelley, M. L., & Stokes, T. F. (1982). Contingency contracting with disadvantaged youths: Improving classroom performance.
Παραπομπή Chicago StyleKelley, Mary Lou, και Trevor F. Stokes. Contingency Contracting With Disadvantaged Youths: Improving Classroom Performance. 1982.
Παραπομπή MLAKelley, Mary Lou, και Trevor F. Stokes. Contingency Contracting With Disadvantaged Youths: Improving Classroom Performance. 1982.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.