4. Kunci lembar kerja
Tidak ada
5. Referensi
Irwin, D. M., & Bushnell, M. (1980). Observational Strategies for Child Study.
Holt, Rinehart and Winston, Newyork.
Kerlinger, F.N. (1996). Asas-asas Penelitian Behavioral. Gajah Mada University
Press : Yogyakarta
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