Chromatic Homotopy Theory
《Chromatic Homotopy Theory》 · 第 278 页 · Section 9.2.5，Definition 9.2.13 及其前一句
A connected sum \(M_1\#M_2\) is trivial if either \(M_1\) or \(M_2\) is a sphere. A connected, oriented 3-manifold \(M\) is prime if every connected sum \(M=M_1\#M_2\) is trivial.