If you use sequential SuperLU, please cite:
@article{superlu99, 
    author  = {James W. Demmel and Stanley C. Eisenstat and 
               John R. Gilbert and Xiaoye S. Li and Joseph W. H. Liu},
    title   = {A supernodal approach to sparse partial pivoting},
    journal = {SIAM J. Matrix Analysis and Applications}, 
    year    = {1999}, 
    volume  = {20},
    number  = {3},
    pages   = {720-755}
}
If you use SuperLU_MT (for shared-memory parallel machines), please cite:
@article{superlu_smp99, 
    author  = {James W. Demmel and John R. Gilbert and Xiaoye S. Li},
    title   = {An Asynchronous Parallel Supernodal Algorithm for 
                 Sparse Gaussian Elimination},
    journal = {SIAM J. Matrix Analysis and Applications},
    year    = {1999}, 
    volume  = {20},
    number  = {4},		  
    pages   = {915--952}
}
If you use SuperLU_DIST (for distributed-memory parallel machines), please cite:
@article{lidemmel03,
     AUTHOR = {Xiaoye S. Li and James W. Demmel},
     TITLE = {{SuperLU_DIST}: A Scalable Distributed-Memory Sparse Direct
              Solver for Unsymmetric Linear Systems},
     JOURNAL = {ACM Trans. Mathematical Software},
     YEAR = 2003,
     MONTH = {June},
     VOLUME = {29},
     NUMBER = {2},
     PAGES = {110--140}
}