Study of B c →J/ψ π, η c π decays with perturbative QCD approach Junfeng Sun, Dongsheng Du and Yueling Yang Eur. Phys. J. C, 60 1 (2009) 107-117 Published online: 07 February 2009 DOI: 10.1140/epjc/s10052-009-0872-y