1. Agrawal, D. C., Pawar, S. S., and Mascarenhas, A. F. 1993. Cryopreservation of spores of Cyathea spinulosa Wall. ex. Hook. f. An endangered tree fern. J. Plant Physiol. 142:124–126.
2. Aragón, C. F. and Pangua, E. 2004. Spore viability under different storage conditions in four rupicolous Asplenium L. taxa. Am. Fern J. 941:28–38.
3. Ballesteros, D., Estrelles, E., and Ibars, A. M. 2006. Responses of Pteridophyte spores to ultrafreezing temperatures for long-term conservation in Germplasm Banks. Fern Gazette 17:293–302.
4. Ballesteros, D. and Walters, C. 2007a. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states and storage stability. J. Exp. Bot. 58:1185–1196.
5. Ballesteros, D. and Walters, C. 2007b. Calorimetric properties of water and triacylglycerols in fern spores relating to storage at cryogenic temperatures. Cryobiology 55:1–9.