Krieghbaum, H. (1969). An Investment in Knowledge: The first dozen years of the National Science Foundation's summer institutes programs to improve secondary shool science and mathematics teaching, 1954-1965. Univ.Pr..
Cita Chicago (17th ed.)Krieghbaum, Hillier. An Investment in Knowledge: The First Dozen Years of the National Science Foundation's Summer Institutes Programs to Improve Secondary Shool Science and Mathematics Teaching, 1954-1965. NewYork: Univ.Pr., 1969.
Cita MLA (9th ed.)Krieghbaum, Hillier. An Investment in Knowledge: The First Dozen Years of the National Science Foundation's Summer Institutes Programs to Improve Secondary Shool Science and Mathematics Teaching, 1954-1965. Univ.Pr., 1969.
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