Singhal, R.M. and Sharma, S.D. 1979. Infra-red Spectroscopy of the Soil Humic Acids of the Sal (<I>Shorea robusta</I>) Forests of Doon Valley. Indian Forester. 105, 9 (Sep. 1979), 658–663. DOI:https://doi.org/10.36808/if/1979/v105i9/11359.