BioStor
 | Some Pteridosperm Stems and Fructifications with Particular Reference to the Medullosae Robert W Baxter (1949) Annals of the Missouri Botanical Garden 36: 287-353 |
 | Phylogenetic Analysis of Seed Plants and the Origin of Angiosperms Peter R Crane (1985) Annals of the Missouri Botanical Garden 72: 716-793 |
 | A Reevaluation of Seed Plant Phylogeny Kevin C Nixon, William L Crepet et al. (1994) Annals of the Missouri Botanical Garden 81: 484-533 |
 | Functional Constraints and rbcL Evidence for Land Plant Phylogeny Victor A Albert, Anders Backlund et al. (1994) Annals of the Missouri Botanical Garden 81: 534-567 |