  Mansfield showed how to induce representations of crossed products of
C*-algebras by coactions from crossed products by quotient groups and proved an
imprimitivity theorem characterising these induced representations. We give an
alternative construction of his bimodule in the case of dual coactions, based
on the symmetric imprimitivity theorem of the third author; this provides a
more workable way of inducing representations of crossed products of
C*-algebras by dual coactions. The construction works for homogeneous spaces as
well as quotient groups, and we prove an imprimitivity theorem for these
induced representations.
