upward

Continuum models

Ram-Mohan L R, Yoo K H, Wavefunction engineering of layered semiconductors: theoretical foundations, JPC 18, R901 (2006)

B A Foreman, Theory of the effective Hamiltonian for degenerate bands in an electric field, JPC 12, R435 (2000)

Nenciu G, Dynamics of band electrons in electric and magnetic fields: rigorous justification of the effective Hamiltonians, RMP 63, 91 (1991)

Luttinger J M, Kohn W, Motion of electrons and holes in perturbed periodic fields, PR 97, 869 (1955)