  Bottomonium-like resonances Zb(10610) and Zb'(10650) are good candidates of
hadronic molecules composed of BBbar* (or B*Bbar) and B*Bbar*, respectively.
Considering Zb (Zb') as heavy meson molecules, we investigate the decays of
Zb(')^+ -> Upsilon (nS) pi^+$ in terms of the heavy meson effective theory. We
find that the intermediate B (B*) and Bbar (Bbar*) meson loops and the form
factors play a significant role to reproduce the experimental values of the
decay widths. We also predict the decay widths of Zc^+ -> J/\psi pi^+ and
psi(2S) pi^+ for a charmonium-like resonance Zc which has been reported
recently in experiments.
