(1963). Teacher's manual for interaction and systems: A science unit for the primary grades (Trial ed.). University of California.
Chicago-viite (17. p.)Teacher's Manual for Interaction and Systems: A Science Unit for the Primary Grades. Trial ed. California: University of California, 1963.
MLA-viite (9. p.)Teacher's Manual for Interaction and Systems: A Science Unit for the Primary Grades. Trial ed. University of California, 1963.
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