1. Beddome, R. H. (1868). Ferns of British Indian Vol.2. Beddome, Rep. 2009, Bishen Singh Mahendra Pal Singh, Dehradun.
2. Beddome, R.H. (1883). Handbook to the Ferns of British India, Ceylon and the Malay Peninsula: Thacker Spink & Co., Calcutta. https://doi.org/10.5962/bhl.title.101756
3. Beddome, R.H. (1892). Supplement to the Handbook to the Ferns of British India, Ceylon and the Malay Peninsula: 1-110. Thacker Spink & Co., Calcutta. https://doi.org/10.5962/bhl.title.49551
4. Chandra, S. and Fraser-Jenkins, C.R. (2008). Threatened Pteridophytes of India. In: SC Verma, SP Khullar & HK Cheema (editors): Perspectives in Pteridophytes, Bishen Singh Mahendra Pal Singh, Dehradun.
5. Chandra, S., Fraser-Jenkins, C. R., Kumari, A. and Srivastava, A. (2008). A Summary of the Status of Threatened Pteridophytes of India. Taiwania, 53 (2): 170-209.
6. Clarke, C.B. (1880). A review of the ferns of northern India etc., Trans. Linn.Soc. (Lond.), ser. 2, Bot. 1: 425-619 et tt. https://doi.org/10.1111/j.1095-8339.1880.tb00197.x
7. Desmond, R. (1992). The European Discovery of the Indian Flora. Royal Botanic Gardens, Oxford University Press.
8. Dixit, R. D. (1984). A Census of the Indian Pteridophytes, Flora of India, ser. 5: 1-177. Botanical Survey of India, Howrah.
9. Ebihara, A., Fraser-Jenkins, C. R., Parris, B. S., Zhang, X.-C., Yang, Y.-H., Chiou, W.-L., Chang, H.-M., Lindsay, S., Middleton, D., Kato, M., Praptosuwiryo, T. N., Amoroso, V., Barcelona, J. F., Rajapaksha, R. H. G., Park, C.-H., Murakami, N. and Hoya, A. (2012). Rare and threatened pteridophytes of Asia 1. An enumeration of narrowly distributed taxa. Bull. Natl. Mus. Nat. Sci., Ser. B. 38: 93-119.
10. Fraser-Jenkins, C. R. (2012). Rare and Threatened Pteridophytes of Asia 2. Endangered Species of India - the Higher IUCN Categories. Bull. Natl. Mus. Nat. Sci., Ser. B. 38 (4): 153-181.
11. Hooker, J.D. (1849). The Rhododendrons of Sikkim Himalaya; Being an account, Botanical and Geographical of the Rhododendrons recently discovered in the mountains of Eastern Himalaya, Drawings and descriptions made on the spot, During a government botanical mission to that country (ed. W. J. Hooker) Rep.1979, Bishen Singh Mahendra Pal Singh, Dehradun. https://doi.org/10.5962/bhl.title.11178
12. Hooker, J. D. (1854). Himalayan Journals, Notes of a Naturalist in Bengal, The Sikkim and Nepal Himalayas and Khasia Mountains & c. John Murray, Albemarle Street. London. https://doi.org/10.5962/bhl.title.60447
13. Hooker, W.J. (1864). Species Filicum etc. vol 5 : [Rep.1970.] J. Cramer, Lehre.
14. Hooker, W.J. and Baker, J.G. (1868). Synopsis filicum, a synopsis of all known ferns including the "Osmundaceae, Schizaeaceae, Marattiaceae and Ophioglossaceae", Rep. 1984, M/s Bishen Singh Mahendra Pal Singh, Dehradun.
15. Hovenkamp, P.H. (1986). A monograph of the fern genus Pyrrosia (Polypodiaceae). Leiden Bot. Ser. 9: 1-310. E.J. Brill, Leiden University Press, Leiden.
16. Kholia, B.S. (2011). Pteridophytic wealth of Sikkim Himalaya. In Biodiversity of Sikkim. ed.. M. L. Arrawatia and Sandeep Tambe. Chapter 3. Ferns. 35-68.
17. Kholia, B. S. (2014). Ferns and Fern-allies of Sikkim, A Pictorial Handbook Part-II. Sikkim state Biodiversity Board & Botanical Survey of India, Sikkim, Gangtok.
18. Ludlow, F. (1972). Thomas J. Booth and the type localities of his Indian rhododendrons described by Nuttall. Transactions Botanical Society of Edinburgh, 41: 351-363. https://doi.org/10.1080/03746607208685238
19. McNeill , J. , Barrie , F. R. , Buck , W. R . , Demoulin, V. , Greuter, W. , Hawksworth, D. L. & al. (eds) (2012 ). International Code of Nomenclature for algae, fungi and plants (Melbourne Code). Adopted by the Eighteenth International Botanical Congress, Melbourne, Australia, July 2011. A. R. G. Gantner Verlag KG/Ruggell: [Regnum Veg. 154] .
20. Mehra, P.N. and Bir, S.S. (1964). Pteridophytic flora of Darjeeling and Sikkim Himalayas. Res. Bull. Panjab. Univ. n.s. 15(1-2): 69-181.
21. Noltie, H. J. (1983). Flora of Bhutan including a record of plants from Sikkim and Darjeeling. Royal Botanic Garden, Edinburgh.
22. Nuttall, T. (1853). Description of and observations on some species of Rhododendron, collected in Assam and Bootan by Thomas J. Booth. Hooker's Journal of Botany and Kew Garden Miscellany, 5: 353-67.
23. Satija C. K., Bir, S. S. and Bhardawaj, A. K. (1983). Taxonomic revision of the Polypodiaceous genera of India Pyrrosia Mirbel. Bull. Bot. Surv. India. 25 (1-4): 62-89.