Could you please help me with the following three SPE papers? Many thanks.

A. Behie. 1985. Comparison of Nested Factorization, Constrained Pressure Residual, and Incomplete Factorization Preconditionings, SPE Reservoir Simulation Symposium, 10-13 February 1985, Dallas, Texas

Choongyong Han, SPE, Chevron ETC, John Wallis, SPE, Wallis Consulting Inc., Pallav Sarma, SPE, Gary Li, SPE, Mark L. Schrader, SPE, Wen Chen, SPE, Chevron ETC. 2011. Enhancement of the CPR Preconditioner for Efficient Solution of the. SPE Reservoir Simulation Symposium, 21-23 February 2011, The Woodlands, Texas, USA

Clees, T. and Ganzer, L. 2010. An Efficient Algebraic Multigrid Solver Strategy for Adaptive Implicit Methods in Oil-Reservoir Simulation. SPE J. 15 (3): 670-681. SPE-105789-PA. doi: 10.2118/105789-PA.