The Amalgamated product of free groups and residual solvability
  In this paper we study residual solvability of the amalgamated product of two finitely generated free groups, in the case of doubles. We find conditions where this kind of structure is residually solvable, and show that in general this is not the case. However this kind of structure is always meta-residually-solvable. 
Delaram Kahrobaei (University of St Andrews)