Golovashkin A.I. , Ivanenko O.M. , Anshukova N.V. , Bugoslavkisy Y.V. , Veselago V.G. , Ershov O.V. , Zaytzev I.A. , Mitzen K.V. , Minakov A.A. The effect of oxygen content variation and rare-earth ion substitution on the magnetic properties and specific heat of the granular high-T_c superconductors. Acta phys. pol. A , Vol.76,N1 , с. C.35-40 , 01.1989