APA (7th ed.) Citation

Eigen, L. D. (1960). Some problems in field testing programs for teaching machines. Center for Programed Instruction.

Chicago Style (17th ed.) Citation

Eigen, Lewis D. Some Problems in Field Testing Programs for Teaching Machines. N.Y.: Center for Programed Instruction, 1960.

MLA (8th ed.) Citation

Eigen, Lewis D. Some Problems in Field Testing Programs for Teaching Machines. Center for Programed Instruction, 1960.