Bott, S., Bott, S., Yang, K., Talafuse, K., & Richmond, M. (2003). Phosphine Ligand Attack at Both the Methylidyne Cap and the CpNi Center in HCCo2NiCp(CO)6by 2,3-Bis(diphenylphosphino)maleic Anhydride (bma):   P−C Bond Cleavage Reactivity, Kinetics, and X-ray Structures of the Zwitterionic Clusters Co2NiCp(CO)4(μ-CO)[μ2,η2,η1-C(H)PPh2CC(PPh2)C(O)OC(O)] and Co2NiCp(CO)4[μ2,η2,σ-C(H)PPh2CCC(O)OC(O)](μ2-PPh2). Organometallics, 22(7), pp. 1383-1390. doi:10.1021/om0209273

Bott, Simon, SG Bott, KY Yang, KA Talafuse, and MG Richmond. "Phosphine Ligand Attack At Both the Methylidyne Cap and the CpNi Center in HCCo2NiCp(CO)6by 2,3-Bis(diphenylphosphino)maleic Anhydride (bma):   P−C Bond Cleavage Reactivity, Kinetics, and X-ray Structures of the Zwitterionic Clusters Co2NiCp(CO)4(μ-CO)[μ2,η2,η1-C(H)PPh2CC(PPh2)C(O)OC(O)] and Co2NiCp(CO)4[μ2,η2,σ-C(H)PPh2CCC(O)OC(O)](μ2-PPh2)." Organometallics 22, no. 7 (2003): 1383-1390.

Bott, Simon, et al. "Phosphine Ligand Attack At Both the Methylidyne Cap and the CpNi Center in HCCo2NiCp(CO)6by 2,3-Bis(diphenylphosphino)maleic Anhydride (bma):   P−C Bond Cleavage Reactivity, Kinetics, and X-ray Structures of the Zwitterionic Clusters Co2NiCp(CO)4(μ-CO)[μ2,η2,η1-C(H)PPh2CC(PPh2)C(O)OC(O)] and Co2NiCp(CO)4[μ2,η2,σ-C(H)PPh2CCC(O)OC(O)](μ2-PPh2)." Organometallics 22.7 (2003): 1383-1390.