Pennsylvania Dept of Public Instruction. (1963). Science in action. Dept. of Public Instruction.
Chicago-viite (17. p.)Pennsylvania Dept of Public Instruction. Science in Action. Harrisburg, Pa: Dept. of Public Instruction, 1963.
MLA-viite (9. p.)Pennsylvania Dept of Public Instruction. Science in Action. Dept. of Public Instruction, 1963.
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