(1968). Populations: A science unit for the primary grades (Trial ed.). Science Curriculum Improvement Study.
Citazione stile Chigago Style (17a edizione)Populations: A Science Unit for the Primary Grades. Trial ed. Berkeley, CA: Science Curriculum Improvement Study, 1968.
Citatione MLA (9a ed.)Populations: A Science Unit for the Primary Grades. Trial ed. Science Curriculum Improvement Study, 1968.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.