Jacobson, A. (1992). Think, think, think now!: Material and methods for problem solving. Phoenix Pub.
Chicago-viite (17. p.)Jacobson, Andrew. Think, Think, Think Now!: Material and Methods for Problem Solving. Quezon City: Phoenix Pub, 1992.
MLA-viite (9. p.)Jacobson, Andrew. Think, Think, Think Now!: Material and Methods for Problem Solving. Phoenix Pub, 1992.
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