Citation: Matthew B. Harney; Richard J. Keaton; James C. Fettinger; Lawrence R. Sita (2006). Living Ziegler-Natta Polymerization by Early Transition Metals: Synthesis and Evaluation of Cationic Zirconium Alkyl Complexes Bearing \b-Hydrogens as Models for Propagating Centers. Journal of the American Chemical Society, 128, pp. 3420-3432.