authors, Hiltrud Hein ... [et al.] ; editors, Hartmut Bergmann ... [et al.] ; chief editor, Hartmut Bergmann ; C11a : gw - C11b : us. -- Springer, 1990-1991. -- (Gmelin handbook of inorganic chemistry / prepared and issued by Gmelin-Institut für Anorganische Chemie der Max-Planck-Gesellschaft zur Förderung der Wissenschaften ; director, Ekkehard Fluck ; system no. 39 . Sc, Y, La-Lu, rare earth elements).