004140000a2200133000450024500710000065000090007165000190008065000240009965000240012304100130014770000210016010000220018177300770020310aSpatial patterns in the species richness of birds in the New World14aAves14aBiogeografía14aPatrones espaciales14aRiqueza de especies0 aInglés1 aGaston, Kevin J.1 aBlackburn, Tim M.1 tEcography: pattern and diversity in ecology31136h19q369-376d1996g19