On Porostrobus zeilleri, Nathorst, and its spores with remarks on the systematic position of Porostrobus bennholdi, Bode, and the Phyogeny of Densosporites, Berry.
Reference:
Bharadwaj,D.C. (1959)
On Porostrobus zeilleri, Nathorst, and its spores with remarks on the systematic position of Porostrobus bennholdi, Bode, and the Phyogeny of Densosporites, Berry. The Palaeobotanist
Vol. 7 # 1 P. 67- 75