“DEVELOPMENT AND VALIDATION OF A SENSITIVE LC–MS METHOD FOR THE DETERMINATION OF FOUR POTENTIAL IMPURITIES (LAS-I, LAS-II AND THEIR REGIOISOMERS) IN LASMIDITAN DRUG SUBSTANCE AT PPM LEVELS”, int. J. Eng. Res. Sci. Tech., vol. 22, no. 4(S), pp. 109–116, Oct. 2026, doi: 10.62643/ijerst.2026.v22.n4(s).4807.