Saltpetre
Hutchinson, C.M.
Saltpetre Its origin and extraction in India - Calcutta 1917 - 1-24 p. - Origin Pusa Agricultural Research Institute. Bulletin No. 68 .
Saltpetre Its origin and extraction in India - Calcutta 1917 - 1-24 p. - Origin Pusa Agricultural Research Institute. Bulletin No. 68 .