SINGLET-GROUND-STATE MAGNETS COUPLED WITH NUCLEAR SPINS. SYSTEMS WITH SINGLET-DOUBLET AND SINGLET-TRIPLET IONS N. Suzuki et Y. Fukuyama J. Phys. Colloques, 49 C8 (1988) C8-1553-C8-1554 DOI: 10.1051/jphyscol:19888711