A. Williams, K. Smith, Z. Bhuiyan, J. Phillips, H. Zhao, and T. Nitta, “Betulinic acid and its ionic derivatives impaired growth of prostate cancer cells without induction of GRP78 and CHOP”, Curr. Issues Pharm. Med. Sci., vol. 35, no. 4, pp. 163–168, Dec. 2022, doi: 10.2478/cipms-2022-0030.