Tucker, R. W; Wang, C (1997). "An Einstein–Proca-fluid model for dark matter gravitational interactions". Nuclear Physics B: Proceedings Supplements. 57 (1–3): 259-262. Bibcode:1997NuPhS..57..259T. doi:10.1016/s0920-5632(97)00399-x.
Tucker, R. W; Wang, C (1997). "An Einstein–Proca-fluid model for dark matter gravitational interactions". Nuclear Physics B: Proceedings Supplements. 57 (1–3): 259-262. Bibcode:1997NuPhS..57..259T. doi:10.1016/s0920-5632(97)00399-x.