Lecturas de ciencias biológicas, escuela intermedia. 

 - Hato Rey, P.R.  División de Currículo  1970. 
 - 204 p.  illus., draws. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Biology--Study and teaching (Secondary)
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Puerto Rico--Biology.