Kamenshchik, Alexander Yu.; Moschellai, Ugo; Pasquier, Vincent (2001), "An alternative to quintessence", Phys. Lett B.511 (2-4): 265, doi:10.1016/S0370-2693(01)00571-8
Bento, M. C.; Bertolami, O.; Sen, A. A. (2002), "Generalized Chaplygin gas, accelerated expansion and dark energy-matter unification", Phys. Rev.66 (4): 043507, doi:10.1103/PhysRevD.66.043507
