Ethylene coordination, insertion, and chain transfer at a cationic aluminum center: A comparative study with Ab Initio correlated level and density functional methods. - Giovanni Talarico; Peter H. M. Budzelaar; Anton W. Gal (J. Comput. Chem., 2000)

Geometry optimization using generalized, chemically meaningful constraints. - Peter H. M. Budzelaar (J. Comput. Chem., 2007)