(p,q)-string in the wrapped supermembrane on 2-torus -- A classical   analysis of the bosonic sector --
  We consider a wrapped supermembrane on $\R^9\times T^2$. We examine a double dimensional reduction to deduce a $(p,q)$-string in type IIB superstring theory from the wrapped supermembrane. In particular, directly from the wrapped supermembrane action, we explicitly derive the action of a string which carries the RR 2-form charge as well as the NSNS 2-form charge, and the tension of the string agrees with the $(p,q)$-string tension. 
Hiroyuki Okagawa, Shozo Uehara and Satoshi Yamada