Since 1970 several volumes of the Landolt-Börnstein New Series have appeared which are devoted to, or at least include, the magnetic properties of some special groups of substances. Volume 19 of Group III (Crystal and Solid State Physics) deals with the magnetic properties of metals, alloys and metallic compounds containing at least one transition element. The amount of information available has become so substantial that several subvolumes are needed to cover it all. The first subvolumes deal with the intrinsic magnetic properties, i. e. those magnetic properties which depend only on the chemical composition and the crystal structure. Data on the properties which also depend on the preparation of the samples measured, as for instance, thin films or amorphous alloys and the magnetic alloys used in technical applications, will be compiled in the last subvolumes of the series. The first subvolume, III/19 a, appeared in 1986. It covers the magnetic properties of metals and alloys of the 3d, 4d and 5d transition elements. The second subvolume, III/19 b (1987), covers the magnetic properties of the binary metallic alloys and compounds of 3d transition elements with the elements of group 1B, 2B and 3B of the Periodic System. The present subvolume III/19 c completes the survey of the magnetic data of the metallic compounds of d transition-elements with elements of the main groups of the Periodic System of the elements. The major groups of ternary compounds, i. e. the Heusler alloys and the compounds with perovskite structure, are being treated in separate chapters.