1. Ahmad, T., Harris, N., Bickle, M., Chapman, H., Bunbury, J., and Prince, C. (2000) Isotopic constraints on the structural relationships between the lesser Himalayan series and the high Himalayan crystalline series, Garhwal Himalaya. Geol. Soc. Amer. Bull., v.112(3), pp.467–477.
2. Azad, M.A., Singh, S.K. and Nair, A.S. (2020) Application of Rock Mass Classification Systems for future excavation and support design of proposed Road Tunnel from Khand Birkot to Sarot Doman in Tehri Garhwal District, Uttarakhand. Himalayan Geol., v.41(2), pp.234–240.
3. Barton, N., Lien, R. and Lunde, J. (1974) Engineering classification of rock masses for the design of tunnel support. Rock Mech., v.6(4), pp.189–236.
4. Bieniawski, Z.T. (1989) Engineering rock mass classifications: a complete manual for engineers and geologists in mining, civil, and petroleum engineering. John Wiley & Sons.
5. Heim, A. and Gansser, A. (1939) The Throne of the Gods: An Account of the First Swiss Expedition to the Himalayas. Macmillan.