Binger, P.; Müller, P.; Podubrin, S.; Albus, S.; Krüger, C. Bis(η⁵-cyclopentadienyl)- and bis(η⁵-indenyl)metallacycles of titanium and zirconium from methylenecyclopropanes by oxidative coupling. Journal of Organometallic Chemistry2002, 656, 288–298.