Cătinaş, Daniela. “On a Possible Determination of the Frame Bounds”. Rev. Anal. Numér. Théor. Approx. 29, no. 1 (February 1, 2000): 3–13. Accessed December 23, 2024. https://ictp.acad.ro/jnaat/journal/article/view/2000-vol29-no1-art1.