Nigam, R C Language handbook on mother tongues in census: Census of India 1971 - New Delhi: Office of the registrar general, India Ministry of Home Affairs, 1971 - lxi, 340p. - Census centenary monograph No. 10 . Subjects--Topical Terms: Language classification Subjects--Index Terms: Principal language Universal Decimal Class. No.: I 312:809.5(540) / L2