Shulka, A.C..
Essentials of Paleobotany / - Second Rev. Ed. / - New Delhi-2 : Vikas Publishing House Pvt. Ltd.. - p.377 :
0-7069-1451-1
I:8 / L5S, M2;1
Essentials of Paleobotany / - Second Rev. Ed. / - New Delhi-2 : Vikas Publishing House Pvt. Ltd.. - p.377 :
0-7069-1451-1
I:8 / L5S, M2;1