Ross, John R. (1967). Constraints on variables in syntax (Doctoral dissertation). Massachusetts Institute of Technology. hdl:1721.1/15166. See page iv of the ms., page 4 of the electronic file.
Will Sweetman, Indology mailing list, citing Dieter Henrich, 'Die "wahrhafte Schildkröte"' Hegel-Studien 2 (1963), pp. 281-91, and J. Charpentier, 'A Treatise on Hindu Cosmography from the Seventeenth Century (Brit. Mus. MS. Sloane 2748 A).' Bulletin of the School of Oriental Studies, University of London 3(2) (1924), pp. 317-342.