Vullo, R. & Villalobos-Segura, E. & Amadori, M. & Kriwet, J. & Frey, E. & González, M.A.G. & Gutiérrez, J.M.P. & Ifrim, C. & Stinnesbeck, E.S. & Stinnesbeck, W. (2024)
Exceptionally preserved shark fossils from Mexico elucidate the long-standing enigma of the Cretaceous elasmobranch Ptychodus. Proceedings of the Royal Society B-Biological Sciences, 291(2021), Article 20240262
DOI: 10.1098/rspb.2024.0262

Vullo, R. & Frey, E. & Ifrim, C. & González, M.A. & Stinnesbeck, E.S. & Stinnesbeck, W. (2021)
Manta-like planktivorous sharks in Late Cretaceous oceans. Science, 371(6535), 1253–1256
DOI: 10.1126/science.abc1490

Giersch, S. & Frey, E. & Ifrim, C. & Stinnesbeck, W. & Gonzales Gonzales, A.H. (2010)
Ptychodontid sharks from the Upper Cretaceous locality Vallecillo (North-eastern Mexico) [Abstract]. In Fifth international meeting on Mesozoic fishes – Universidad Autonoma de Estado de Hidalgo: 43

Stinnesbeck, W. & López-Oliva, J.G. & Frey, E. & Ifrim, C. & Giersch, S. (2008)
Comments on "The oldest stratigraphic record of the Late Cretaceous shark Ptychodus mortoni Agassiz, from Vallecillo, Nuevo León, northeastern Mexico'' by Blanco-Piñón et al., Rev. Mex. Cienc. Geol. (2007), 24, 25-30 Revista Mexicana de Ciencias Geológicas, 25(2), 365–366

Ifrim, C. & Frey, E. & Stinnesbeck, W. & Buchy, M.-C. & González González, A.H. & López Oliva, J.G. (2005)
Fish assemblage in Lower Turonian carbonates at Vallecillo, N.L., México. Paleos Antiguo, 1, 43–51