G. Kadereit, S. Hohmann & J. W. Kadereit: A synopsis of Chenopodiaceae subfam. Betoideae and notes on the taxonomy of Beta, In: Willdenowia, Volume 36, 2006, p. 9-19. PDF
Romeiras, M.M., Vieira, A., Silva, D.N., Moura, M., Santos-Guerra, A., Batista, D., Duarte, M.C., & Paulo, O.S. (2016). "Evolutionary and Biogeographic Insights on the Macaronesian Beta-Patellifolia Species (Amaranthaceae) from a Time-Scaled Molecular Phylogeny." PLoS One. 2016; 11(3): e0152456. doi:10.1371/journal.pone.0152456
efloras.org
Leila M. Shultz: Beta. In: Flora of North America Editorial Committee (eds.): Flora of North America North of Mexico, Volume 4: Magnoliophyta: Caryophyllidae, part 1., Oxford University Press, New York 2003, ISBN0-19-517389-9.