Gierbolini, Robert E. <br/><br/>
Soil survey of the Ponce area of southern Puerto Rico 
by Roberto Gierbolini E. 
 - [Washington]  Soil Conservation Service  [1979] 
 - iii, 80 p.  illus., 41 map sheets. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Soil surveys--Maps.--Puerto Rico--Ponce Region
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Puerto Rico--Soil.