Elementos de biología (segundo libro). 

 - San Juan, P.R.  1954. 
 - 269 p.  ill., draws 
 - Its [Publicaciones]. Serie  4-no.63 .
<br/><br/><label>LCCN: </label>fel36001832  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Biology--Study and teaching (Secondary)
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Puerto Rico