Sheldon, D. S., & Penick, J. E. (1991). Favorite labs from outstanding teachers, vol.1. National Association of Biology Teachers.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSheldon, Daniel S., और John E. Penick. Favorite Labs from Outstanding Teachers, Vol.1. Reston, VA: National Association of Biology Teachers, 1991.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSheldon, Daniel S., और John E. Penick. Favorite Labs from Outstanding Teachers, Vol.1. National Association of Biology Teachers, 1991.
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