Puttick MN, Morris JL, Williams TA, et al. The Interrelationships of Land Plants and the Nature of the Ancestral Embryophyte. Current Biology. 2018;28(5):733 - 745.e2. doi:10.1016/j.cub.2018.01.063

Schneider H, Russell SJ, Cox CJ, et al. Chloroplast Phylogeny of Asplenioid Ferns based on rbcL and trnL-F Spacer Sequences (Polypodiidae, Aspleniaceae) and its Implications for Biogeography. Systematic Botany. 2004;29(2):260 - 274. doi:10.1600/036364404774195476