SCAD based in Bangkok have published this very interesting summary of strategies that work and don't work. Stray Animal Management Strategies.
Here also are the links to the two reports mentioned:
Guidelines for Dog Population Management W.H.O. Geneva, 1990 (page 74): ‘Removal and killing of dogs should never be considered as the most effective way of dealing with a problem of surplus dogs in the community: it has no effect whatsoever on the root cause of the problem’
Report of W.H.O. Consultation on Dog Ecology Studies, related to Rabies Control, Geneva 22-25 February 1988 (page 11): ‘In
none of the studies did the elimination of dogs by any method have
any significant long-term effect on dog population size’