BRYDON, J. E. Silicified plant asterosclerid preserved in soil. Soil Sci. Soc. Amer. Proc. 1963, 27, 476-477
EFERMOV, I. A. Taphonomy : a new branch of paleontology. Pan-American Geologist. 1940, 74, 81-93
HANDRECK, K. L. A. Studies in silica in the oat plant. IV. Silica content of plant parts in relation to stage of growth, supply of silica, and transpiration. Plant and Soils. 1986, 29, 449-459