USE OF LUMINESCENCE SPECTRA OF ADDUCTS OF EUROPIUM Β -DIKETONATES WITH METHYL-SUBSTITUTED PYRIDINES IN INTERPRETING NMR DATA OBTAINED BY THE USE OF LANTHANIDE SHIFT REAGENTS Article Zolin V.F., Koreneva L.G., Obukhov A.E., Zvolinskii V.P., Kordova I.R. Theoretical and Experimental Chemistry. Kluwer Academic Publishers-Plenum Publishers. Vol. 18. 1982. P. 166-172