https://peeterjoot.com/2018/11/24/phy2403h-quantum-field-theory-lecture-19-pauli-matrices-weyl-spinors-sl2c-weyl-action-weyl-equation-dirac-matrix-dirac-action-dirac-lagrangian-taught-by-prof-erich-poppitz/
PHY2403H Quantum Field Theory. Lecture 19: Pauli matrices, Weyl spinors, SL(2,c), Weyl action, Weyl equation, Dirac matrix, Dirac action, Dirac Lagrangian. Taught by Prof. Erich Poppitz