Orkin, M., & Drogin, R. (1977). Vital statistics. Tata McGraw-Hill.
Chicago Edition CitationOrkin, Michael, i Richard Drogin. Vital Statistics. New Delhi: Tata McGraw-Hill, 1977.
Cita MLAOrkin, Michael, i Richard Drogin. Vital Statistics. Tata McGraw-Hill, 1977.
Atenció: Aquestes cites poden no estar 100% correctes.