  A major experimental program is presently underway to determine the Sivers,
Boer-Mulders and transversity distributions, vital for understanding the
internal structure of the nucleon. To this end we consider the Sivers,
Boer-Mulders and transversity azimuthal asymmetries of the difference cross
sections of hadrons with opposite charges in SIDIS reactions with unpolarized
and transversely polarized target l+N\to l'+h+X, h=\pi^\pm, K^\pm, h^\pm. We
show that on deuteron target these asymmetries are particularly simple and
determine the sum of the valence-quark Q_V=u_V+d_V transverse momentum
dependent distributions without any contributions from the strange or other
sea-quark functions. At present, data on these asymmetries are presented for
the integrated asymmetries i.e. the x_B- and z_h-dependent asymmetries. If data
are available in small bins in Q^2, so that Q^2-dependence can be neglected,
these expressions simplify dramatically leading to remarkably simple and
powerful tests of the simplifying assumptions used in extracting these
functions from the data.
