1. Bond, Methods of Programmed Instruction Re-Student Characteristics, Educational Resources Information Center, No. 003 335, 1965.
2. Read General Science Test Manual, Harcourt, Brace and World, Chicago, 1965.
3. and , Watson-Glaser Critical Thinking Appraisal Manual, Harcourt, Brace and World, New York, 1954.
4. and , Test on Understanding Science Manual, Education Resources Information Center, No. Ed. 010 091, 1961.