1. Black, C.A. (1965). Methods of Soil Analysis. Part-II, Amer. Soc. Agro., Inc., Publisher Madison, Wisconsin, U.S.A. https://doi.org/10.2134/agronmonogr9.1
2. Banerjee, S.K. and Chakraborty, A.K. (1977). Distribution and nature of organic matter in the surface soils of West Bengal. J. Indian Soc. Soil Sci. 25 (1): 18 - 22
3. Dhir, R.P. (1967). Pedological characteristics of some soils of north – western Himalayas. J. Indian Soc. Soil Sci. 15(1): 61 – 69
4. Dhir, R.P. (1973). A study on the composition of humus in some soil profile of the North – Western Himalayas. J. Indian Soc. Soil Sci. 21 (2): 149 - 154
5. Durgin, P.B. (1980). Organic matter contents of soil after logging of fir and redwood forests Research Note PSW – 346, 4p, pecific Southwest Forest and Range Expt. Station, Berkely, California, U.S.A. https://doi.org/10.2737/PSW-RN-346
6. Eswaran, H., Reich P.F., Kimble, J.M., Beinroth, FH, Padmanabhan E, Moncharoen, P.(...) Global Climate Change and Pedogenic Carbonates Edited by: Lal R, et al. Lewis Publishers, Fl, USA; 1999:15-25
7. Gangopadhyay, S.K., Debnath, N.C. and Banerjee, S.K. (1986). Characteristics of some high altitude soils of Sikkim Forest Division. J. Indian Soc. Soil Sci. 34: 830 - 838
8. Gangopadhyay, S.K., Das, P.K., Mukhopadhyay, N, Nath, S. and Banerjee, S.K. (1990). Altitudinal pattern of soil characteristics under forest vegetation in Eastern Himalayan Region. J. Indian Soc. Soil Sci. 38: 93 - 99
9. Greenland, D.J. and Nye, P.H. (1959). Increase in the carbon and nitrogen contents of tropical soils under natural fallows. J. Soil Sci. 10: 284 – 299. https://doi.org/10.1111/j.1365-2389.1959.tb02350.x
10. Gupta, R. D., Tripathi, B. R. and Banerjee, S.K. (1982). Composition and nature of humus in some soils of North – west Himalayas as influence by vegetation climate and parent rock. J. Indian Soc. Soil Sci. 30 (4): 468 – 476. http://karnet.up.wroc.pl/- Properties of humic substances
11. Kononova, M.M. (1966). Soil Organic Matter. It’s Nature, its role in Soil formation and in Soil fertility. Pergamon Press Ltd., Headington Hill Hall, Oxford, London
12. Krishan, G., Srivastava, S.K., Kumar, S, Saha, S.K. and Dadhwal, V.K. (2009). Quantifying the underestimation of soil organic carbon by the Walkley and Black technique - example from Himalyan and Central Indian Soils. Current Science, 96(8): 1133- 1136
13. Mandal, A.K., Nath, S., Gupta, S.K. and Banerjee, S.K. (1990). Characteristics and nutritional status of soil of middle hill and upper hill forest of the Eastern Himalayas. J. Indian Soc. Soil Sci. 38: 100-106
14. Minhas, R. S. and Bora, N.C. (1982). Distribution of organic carbon and the form of nitrogen in a topographic sequence of soils. J. Indian Soc. Soil Sci. 30 (2): 135-139
15. Mukhopadhyay, N., Gupta, S.K. and Banerjee, S.K. (1982). Forms and distribution of humic and fulvic acid components in soil under deciduous and coniferous forests. J. Indian Soc. Soil Sci. 30(4): 477 – 488
16. Pettit, R.E. (2012). Organic Matter, Humus, Humate, Humic Acid, Fulvic Acid, and Humin: Their impotance in soil fertility and plant health (Online). Available at: http://fertiorganicos.com/english/images/lib/ORGANIC_MATTER_HUMUS_HUMATE_HUMIC_ACID_FULVIC_ACID.pdfCT/Research
17. Pettit, R.E. (2004). Organic Matter, Humus, Humate, Humic Acid, Fulvic Acid, and Humin: Their impotance in soil fertility and plant health (Online). Available at: http://fertiorganicos.com/english/images/lib/ORGANIC_MATTER_HUMUS_HUMATE_HUMIC_ACID_FULVIC_ACID.pdfCT/Research.1-15
18. Puri, G. S. and Gupta, A.C. (1951). The Himalayan conifers II. The ecology of humus in conifers forests of Kulu Himalayas. Indian Forester, 77 (1): 55-63
19. Walkley, A. (1946). A critical examination of rapid method for determining organic carbon in soils – effect of variations in digestion conditions and of inorganic soil constituents. Soil Sci. 63: 251 – 263 https://doi.org/10.1097/00010694-194704000-00001