↑Taylor, Thomas N.; Edith L. Taylor (1993). The Biology and Evolution of Fossil Plants. Englewood Cliffs, NJ: Prentice Hall. с. 138, 197. ISBN0-13-651589-4.
Taylor, Thomas N.; Edith L. Taylor (1993). The Biology and Evolution of Fossil Plants. Englewood Cliffs, NJ: Prentice Hall. с. 138, 197. ISBN0-13-651589-4.