Mathematical Physics: Classical Mechanics
《Mathematical Physics: Classical Mechanics》 · 第 133 页 · Chapter 13 首段，framed link 的 linking matrix 定义
A framed link (with components temporarily ordered and oriented) has a linking matrix. This is the symmetric matrix with entries the linking numbers between the pairs of components of the link. The linking number of a component with itself (a diagonal term of the matrix) is taken to be the integer that gives the framing of that component.