Gruber, H. E., & Piaget, J. (1981). Darwin on man: A psychological study of scientific creativity / Howard E. Gruber. Foreword to the first ed. by Jean Piaget (2. ed.). Univ. of Chicago Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रGruber, Howard E., और Jean Piaget. Darwin on Man: A Psychological Study of Scientific Creativity / Howard E. Gruber. Foreword to the First Ed. by Jean Piaget. 2. ed. Chicago: Univ. of Chicago Press, 1981.
एमएलए (8वां संस्करण) प्रशस्ति पत्रGruber, Howard E., और Jean Piaget. Darwin on Man: A Psychological Study of Scientific Creativity / Howard E. Gruber. Foreword to the First Ed. by Jean Piaget. 2. ed. Univ. of Chicago Press, 1981.
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