Complex sentence: There is another kind of scale-free model, which grows according to some patterns, such as the (hierarchical network model) E. Ravasz and Barabási Phys. Rev. E 67,026112 (2003).
Split into simpler sentences: There is another kind of scale-free model. Such as hierarchical network model E. Ravasz and Barabasi Phys. Rev. E 67,026112 (2003).