It has long been suggested that star formation in giant molecular clouds
 may be triggered by external perturbations such as cloud-cloud collisions.
 Several observational studies of particular molecular clouds have
 supported this assertion: Cloud-cloud collisions are suggested to be
 occurring in NGC 1333, IRAS 19550+3248, IRAS 2306+1451, W49N and Sgr B2.
 Observations taken with the Australia Telescope Compact Array, the Mopra
 telescope and the Swedish-ESO Submillimetre Telescope (SEST) suggest that
 cloud-cloud collisions are also occurring in the southern giant molecular
 clouds G1.6-0.025, G265.1+1.5 (RCW 36) and G291.3-0.7 (RCW 57). The
 evidence for RCW36 and RCW 57 is presented here.