Cita APA (7th ed.)
Duggal,S.K. (2013). Surveying (4th ed.). McGraw-Hill.
Cita Chicago (17th ed.)
Duggal,S.K. Surveying. 4th ed. New Delhi: McGraw-Hill, 2013.
Cita MLA (9th ed.)
Duggal,S.K. Surveying. 4th ed. McGraw-Hill, 2013.
Atenció: Aquestes cites poden no estar 100% correctes.