Cita APA (7th ed.)

Pattis, R. E. (1981). Karel the robot: A gentle introduction to the art of programming. Wiley.

Cita Chicago (17th ed.)

Pattis, Richard E. Karel the Robot: A Gentle Introduction to the Art of Programming. N.Y: Wiley, 1981.

Cita MLA (9th ed.)

Pattis, Richard E. Karel the Robot: A Gentle Introduction to the Art of Programming. Wiley, 1981.