Magnetization, Magnetic Susceptibility and ESR in Tb3Ga5O12
  We report on the measurement of the magnetic susceptibility and of ESR transitions in the garnet substance Tb$_3$Ga$_5$O$_{12}$ (TGG). The results are compared with a calculation in the framework of crystal field theory for the orthorhombic surroundings of the six inequivalent Tb ions of TGG. We also present a calculation of the magnetization for the three main crystal directions. 
U. L\"ow, S. A. Zvyagin, M. Ozerov, U. Schaufuss, V. Kataev, B. Wolf,   B. L\"uthi
cond-mat.str-el