Integrability of the Gauged Linear Sigma Model for AdS_5xS^5
  Recently, a gauged linear sigma model was proposed by Berkovits and Vafa which can be used to describe the AdS_5xS^5 superstring at finite and zero radius. In this paper we show that the model is classically integrable by constructing its first non-local conserved charge and a superspace Lax "quartet". Quantum conservation of the non-local charge follows easily from superspace rules. 
William D. Linch III, Brenno Carlini Vallilo