Srinivasu, K., J. Venkateswara Rao, N. Appala Raju, and K. Mukkanti. “Simultaneous RP-HPLC Method for the Estimation of Formoterol Fumarate and Tiotropium Bromide in Pharmaceutical Dosage Forms”. Asian Journal of Chemistry 22, no. 5 (March 30, 2010): 3943–3948. Accessed July 18, 2024. https://asianpubs.org/index.php/ajchem/article/view/11633.