Trevisan Secretti, Leonardo, et al. “Simple Method for Simultaneous Quantification of Two New Derivatives of Betulinic and Ursolic Acids With Antimalarial Activity by RP-HPLC-UV-CAD”. Drug Analytical Research, vol. 4, no. 2, Dec. 2020, pp. 31-39, doi:10.22456/2527-2616.108249.