Corduneanu, Silvia-Otilia. “A Density Property of the \(C^\ast\)-Algebra Pap(R) and Its Applications”. Rev. Anal. Numér. Théor. Approx. 27, no. 2 (August 1, 1998): 219–225. Accessed May 3, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1998-vol27-no2-art3.