In this Memoir we establish global Rankin Selberg integrals which dete
rmine the standard L function for the group GL(r) x G' where G' is an
isometry group of a nondegenerate symmetric form. The class of automor
phic representations considered here is for any pair Pi(1) circle time
s Pi(2) where Pi(1) is generic cuspidal for GL(r)(A) and Pi(2) is cusp
idal for G'(A). The constructon of these L functions involves the use
of certain new ''models'' of local representations; these models gener
alize the usual generic models. Also we compute local unramified facto
rs in a new way using geometric ideas.