CONTENT AND RATIO OF GROUPS AND FORMS OF IRON COMPOUNDS IN THE VOLCANIC SOILS OF COSTA-RICA Article VEGA O.T. Soviet Soil Science. Vol. 12. 1980. P. 545-553
OBSERVATION OF A PATIENT WITH SOFT CHANCRE Article TISHCHENKO L.D., GAGAEV G.K., GORYACHKOVSKAYA A.K. Vestnik Dermatologii i Venerologii. 1980. P. 63-63