https://peeterjoot.com/2014/09/23/ece1254h-modeling-of-multiphysics-systems-lecture-2-assembling-system-equations-automatically-taught-by-prof-piero-triverio/
ECE1254H Modeling of Multiphysics Systems. Lecture 2: Assembling system equations automatically. Taught by Prof. Piero Triverio