``Representability for some moduli stacks of framed sheaves.''

In DVI, PDF, or postscript.  Manuscripta Mathematica 109 (2002), 85--91.

Proves that, for a curve in a surface with positive normal bundle, most fibers
of the restriction map from the moduli stack of torsion-free sheaves on the surface
to the moduli stack of vector bundles on the curve are actually schemes.