  In this paper the author generalizes the $\E$ and $\N$-type resolutions used
by Martin-Deschamps and Perrin to subschemes of pure codimension in projective
space, and shows that these resolutions are interchanged by the mapping cone
procedure under a simple linkage. Via these resolutions, Rao's correspondence
is extended to give a bijection between even linkage classes of subschemes of
pure codimension two and stable equivalence classes of reflexive sheaves $\E$
satisfying $H^1_*(\E)=0$ and $\ext^1(\E^\vee, \O)=0$. Further, these
resolutions are used to extend the work of Martin-Deschamps and Perrin for
Cohen-Macaulay curves in $\Pthree$ to subschemes of pure codimension two in
$\Pn$. In particular, even linkage classes of such subschemes have the
Lazarsfeld-Rao property and any minimal subscheme for an even linkage class is
directly linked to a minimal subscheme for the dual class.
