Fowler, M.E. (2010). "Medicine and Surgery of Camelids", Ames, Iowa: Wiley-Blackwell. Chapter 1 General Biology and Evolution addresses the fact that camelids (including camels and llamas) are not ruminants, pseudo-ruminants, or modified ruminants.
Fernández, Manuel Hernández; Vrba, Elisabeth S. (1 May 2005). "A complete estimate of the phylogenetic relationships in Ruminantia: a dated species-level supertree of the extant ruminants". Biological Reviews. 80 (2): 269–302. doi:10.1017/s1464793104006670. ISSN1469-185X. PMID15921052. S2CID29939520.
Austin, PJ; et al. (1989). "Tannin-binding proteins in saliva of deer and their absence in saliva of sheep and cattle". J Chem Ecol. 15 (4): 1335–47. doi:10.1007/BF01014834. PMID24272016. S2CID32846214.
Fernández, Manuel Hernández; Vrba, Elisabeth S. (1 May 2005). "A complete estimate of the phylogenetic relationships in Ruminantia: a dated species-level supertree of the extant ruminants". Biological Reviews. 80 (2): 269–302. doi:10.1017/s1464793104006670. ISSN1469-185X. PMID15921052. S2CID29939520.
Austin, PJ; et al. (1989). "Tannin-binding proteins in saliva of deer and their absence in saliva of sheep and cattle". J Chem Ecol. 15 (4): 1335–47. doi:10.1007/BF01014834. PMID24272016. S2CID32846214.
Fernández, Manuel Hernández; Vrba, Elisabeth S. (1 May 2005). "A complete estimate of the phylogenetic relationships in Ruminantia: a dated species-level supertree of the extant ruminants". Biological Reviews. 80 (2): 269–302. doi:10.1017/s1464793104006670. ISSN1469-185X. PMID15921052. S2CID29939520.
Austin, PJ; et al. (1989). "Tannin-binding proteins in saliva of deer and their absence in saliva of sheep and cattle". J Chem Ecol. 15 (4): 1335–47. doi:10.1007/BF01014834. PMID24272016. S2CID32846214.
Ripple, William J.; Pete Smith; Helmut Haberl; Stephen A. Montzka; Clive McAlpine & Douglas H. Boucher. 2014. "Ruminants, climate change and climate policy". Nature Climate Change. Volume 4 No. 1. pp. 2–5.
Fernández, Manuel Hernández; Vrba, Elisabeth S. (1 May 2005). "A complete estimate of the phylogenetic relationships in Ruminantia: a dated species-level supertree of the extant ruminants". Biological Reviews. 80 (2): 269–302. doi:10.1017/s1464793104006670. ISSN1469-185X. PMID15921052. S2CID29939520.