^Naaz, H.; Singh, S.; Pandey, V. P.; Singh, P.; Dwivedi, U. N. (Apr 2013). "Anti-cholinergic alkaloids as potential therapeutic agents for Alzheimer's disease: an in silico approach". Indian J Biochem Biophys. 50 (2): 120–5. PMID23720886.
^Wu, YC; Duh, CY; Wang, SK; Chen, KS; Yang, TH (1990). "Two new natural azafluorene alkaloids and a cytotoxic aporphine alkaloid from Polyalthia longifolia". J. Nat. Prod. 53 (5): 1327–31. doi:10.1021/np50071a028. PMID2292689.