Butts, D. P. (1974). The teaching of science: A self-directed planning guide. Harper & Row.
Lua i Stíl Chicago (17ú heag.)Butts, David P. The Teaching of Science: A Self-directed Planning Guide. New York: Harper & Row, 1974.
Lua MLA (9ú heag.)Butts, David P. The Teaching of Science: A Self-directed Planning Guide. Harper & Row, 1974.
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