  In this paper we give a brief review of our recent studies on the long and
short gamma-ray bursts (GRBs) detected Swift, in an effort to understand the
puzzle of classifying GRBs. We consider that it is still an appealing
conjecture that both long and short GRBs are drawn from the same parent sample
by observational biases.

High Energy Astrophysical Phenomena;Cosmology and Nongalactic Astrophysics