Consult especially Zimmer, Altindisches Leben, Berlin, 1879. On the
home of the Rigvedic Aryans (p. 145) cf. Hopkins, The Panjab and the
Rig-Veda, Journal of the Am. Or. Soc., 1898, p. 19 ff. On the Hamsa
(p. 150) cf. Lanman, The Milk-drinking Hansas of Sanskrit Poetry,
ibid., p. 151 ff. On the Vedic tribes (pp. 153-157), cf. Excursus I. in
Oldenberg's Buddha, Berlin, 1897. On the origin of the castes (p. 160)
cf. Oldenberg, Journal of the Germ. Or. Soc., 1897, pp. 267-290;
R. Fick, Die Sociale Gliederung im nordöstlichen Indien zu Buddha's
Zeit, Kiel, 1897.