Thomas, R.J.; Stanton, D.S.; Longendorfer, D.H.; Farr, M.E. (1978), „Physiological evaluation of the nutritional autonomy of a hornwort sporophyte”, Botanical Gazette, 139 (3): 306—311, S2CID84413961, doi:10.1086/337006
Bateman, R. M.; Dimichele, W. A. (1994). „Heterospory - the most iterative key innovation in the evolutionary history of the plant kingdom”. Biological Reviews of the Cambridge Philosophical Society. 69 (3): 345—417. S2CID29709953. doi:10.1111/j.1469-185x.1994.tb01276.x.
Thomas, R.J.; Stanton, D.S.; Longendorfer, D.H.; Farr, M.E. (1978), „Physiological evaluation of the nutritional autonomy of a hornwort sporophyte”, Botanical Gazette, 139 (3): 306—311, S2CID84413961, doi:10.1086/337006
Bateman, R. M.; Dimichele, W. A. (1994). „Heterospory - the most iterative key innovation in the evolutionary history of the plant kingdom”. Biological Reviews of the Cambridge Philosophical Society. 69 (3): 345—417. S2CID29709953. doi:10.1111/j.1469-185x.1994.tb01276.x.