Takehiko Tanaka Second Difference Method Reinforced by Grouping: A New Tool for Assistance in Assignment of Complex Molecular Spectra. 532-542 2002 conf/dsp/2002 Progress in Discovery Science http://link.springer.de/link/service/series/0558/bibs/2281/22810532.htm db/conf/dsp/dsp2002.html#Tanaka02