  There have been arguments about hadronic molecules, which are weakly-bound
states of two or more hadrons. We investigate the possibility of some
candidates (f0 (980), a0 (980), f0 (1500), f0 (1710), etc.) using QCD sum rule
approach and compare our results with multiquark states in the MIT bag model.
We find that f0 (1500), f0 (1710) can be good candidates for vector-vector
molecule-type multiquark states.
