Kratzmeier, H., Horn, R., & Kratzmeier, H. (1980). Advanced progressive matrices. Advanced progressive matrices [APM].
Chicago Style (17th ed.) CitationKratzmeier, Heinrich, Ralf Horn, and Heinrich Kratzmeier. "Advanced Progressive Matrices." Advanced Progressive Matrices [APM] 1980.
MLA (8th ed.) CitationKratzmeier, Heinrich, et al. "Advanced Progressive Matrices." Advanced Progressive Matrices [APM], 1980.
Warning: These citations may not always be 100% accurate.