APA
Gardner M., Schroeder T., . (1971). Space puzzles. New York: Simon and Schuster.
Chicago
Gardner Martin, Schroeder Ted, . 1971. Space puzzles. New York: Simon and Schuster.
Harvard
Gardner M., Schroeder T., . (1971). Space puzzles. New York: Simon and Schuster.
MLA
Gardner Martin, Schroeder Ted, . Space puzzles. New York: Simon and Schuster. 1971.