Jeffrey Muhr. (1994). World of scientific discovery. Gale Research.
Cita Chicago (17th ed.)Jeffrey Muhr. World of Scientific Discovery. Detroit: Gale Research, 1994.
Cita MLA (9th ed.)Jeffrey Muhr. World of Scientific Discovery. Gale Research, 1994.
Atenció: Aquestes cites poden no estar 100% correctes.