Erwin Brecher & Mike Gerrard. (2009). Challenging Science Puzzles. Goodwill Publishing House.
Chicago Edition CitationErwin Brecher i Mike Gerrard. Challenging Science Puzzles. New delhi: Goodwill Publishing House, 2009.
Cita MLAErwin Brecher i Mike Gerrard. Challenging Science Puzzles. Goodwill Publishing House, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.