EFFECT OF VARIOUS IRON COMPOUNDS ON THE SPECTRAL REFLECTANCE AND COLOR OF SOILS Article KARMANOVA L.A. Soviet Soil Science. Vol. 13. 1981. P. 53-60
MINERAL-COMPOSITION OF VOLCANIC SOILS IN THE TROPICAL REGION OF COSTA-RICA Article GOMEZ V.O., CHERNYAKHOVSKIY A.G., CHIZHIKOVA N.P., SHCHURYGINA Y.A., GRADUSOV B.P. Soviet Soil Science. Vol. 13. 1981. P. 95-102