For Pilea
Boufford, D.E. 1997. Urticaceae. In Flora of North America Editorial Committee. 1997. Flora of North America north of Mexico. Volume 3, Magnoliophyta: Magnoliidae and Hamamelidae. Oxford Univ. Press, New York, NY. 590 pp.
Floden, A.J., and M. Engelhardt. 2019. Pilea fontana (Urticaceae) discovered new to Missouri. Missouriensis 37: 1-5.
Friis In Kubitzki, K., J.G. Rohwer, and V. Bittrich, eds. 1993. The families and genera of vascular plants. II. Flowering plants – Dicotyledons – Magnoliid, Hamamelid and Caryophyllid families. Springer, Berlin. 653 pp.
Fu, L.-F., F. Wen, O. Maurin, M. Rodda, E.M. Gardner, Z.-B. Xin, Y.-G. Wei, and A.K. Munro. 2022. A revised delimitation of the species-rich genus Pilea (Urticaceae) supports the resurrection of Achudemia and a new infrageneric classification. Taxon 71(4): 796-813.