Porter, T. (1967). Physical science: Teaching tips from TST. National Science Teachers Association.
Chicago-viite (17. p.)Porter, T.R. Physical Science: Teaching Tips from TST. Washington, D.C: National Science Teachers Association, 1967.
MLA-viite (9. p.)Porter, T.R. Physical Science: Teaching Tips from TST. National Science Teachers Association, 1967.
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