RT Journal Article SR Electronic T1 A study of some American fossil cycads; Part VII, Further notes on disk structure JF American Journal of Science JO Am J Sci FD American Journal of Science SP 117 OP 136 DO 10.2475/ajs.s4-38.224.117 VO s4-38 IS 224 A1 Wieland, G. R. YR 1914 UL http://www.ajsonline.org/content/s4-38/224/117.abstract AB