L. Lozano, J. Guerra, S. Curbelo, J. Brito, C. Olivera-Fuentes, Synthesis and Characterization of Nipdce/?-Al₂O₃ Catalyst for Selective Hydrogenation of 1,3-butadiene. Impregnation Conditions Study, Chemical Engineering Transactions. 24 (2011) 55-60. doi:10.3303/CET1124010.