Lawrence Richardson, A new topographical dictionary of ancient Rome, Johns Hopkins University Press, 1992, p.47 googlebooks preview. Richardson asserts the single identity of the two heights as Aventine during the Republican era as commonly accepted in modern scholarship. O. Skutsch, "Enniana IV: Condendae urbis auspicia", The Classical Quarterly, New Series, Vol. 11, No. 2 (Nov., 1961), pp. 252-267, argues that they were originally considered and named as separate hills: the Aventine was the northwestern height only, and the slightly lower southeastern height was Mons Murca.
Lawrence Richardson, A new topographical dictionary of ancient Rome, Johns Hopkins University Press, 1992, p.47 googlebooks preview. Richardson asserts the single identity of the two heights as Aventine during the Republican era as commonly accepted in modern scholarship. O. Skutsch, "Enniana IV: Condendae urbis auspicia", The Classical Quarterly, New Series, Vol. 11, No. 2 (Nov., 1961), pp. 252-267, argues that they were originally considered and named as separate hills: the Aventine was the northwestern height only, and the slightly lower southeastern height was Mons Murca.
Carter, Jesse Benedict. "The Evolution of the City of Rome from Its Origin to the Gallic Catastrophe"], Proceedings of the American Philosophical Society, September 2, 1909, pp. 132 - 140. googlebooks preview (link updated 27 November 2010).