@incollection {MR2099450,
    AUTHOR = {Tu, Xuemin and Sarkis, Marcus},
     TITLE = {Singular function enhanced mortar finite element},
 BOOKTITLE = {Domain decomposition methods in science and engineering},
     PAGES = {475--482 (electronic)},
 PUBLISHER = {Natl. Auton. Univ. Mex., M\'exico},
      YEAR = {2003},
   MRCLASS = {65N30 (65N55)},
  MRNUMBER = {2099450},
}