4 papers:
ICFP-2014-GrabmayerR #λ-calculus- Maximal sharing in the λ calculus with letrec (CG, JR), pp. 67–80.
RTA-2010-Schmidt-SchaussSM #call-by #simulation #λ-calculus- Simulation in the Call-by-Need λ-Calculus with letrec (MSS, DS, EM), pp. 295–310.
RTA-2008-Schmidt-SchaussM #call-by #finite #nondeterminism #simulation #λ-calculus- A Finite Simulation Method in a Non-deterministic Call-by-Need λ-Calculus with Letrec, Constructors, and Case (MSS, EM), pp. 321–335.
RTA-2007-Schmidt-Schauss #calculus #correctness- Correctness of Copy in Calculi with Letrec (MSS), pp. 329–343.