A field collector's manual in natural history. 

 - Washington :  The Smithsonian Institution,  1944. 
 - 118 p. :  il. ;  14 cm 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ciencias naturales
<br/><br/><label>Index Terms--Genre/Form: </label><br/>Libro
<br/><br/><label>Universal Decimal Class. No.: </label>579.6