1-Study of polycrystalline Cu2ZnSnS4 films by Raman scattering
http://www.sciencedirect.com/science/article/pii/S0925838811009467
2-Cu2ZnSnS4 as a potential photovoltaic material: A hybrid Hartree-Fock density functional theory study
http://prb.aps.org/abstract/PRB/v79/i11/e115126