Douglas Antony Louis Piriyakumar Paul Levi A novel isomorphism based on nearest neighbours for efficient graph matching algorithm. 722-727 2002 ICARCV http://dx.doi.org/10.1109/ICARCV.2002.1238511 conf/icarcv/2002 db/conf/icarcv/icarcv2002.html#PiriyakumarL02