Grout, Frank F. <br/><br/>
Preliminary report on the clays and shales of Minnesota. 

 - Minneapolis :  The University of Minnesota,  1914. 
 - 172 p. :  il. ;  23 cm 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geología económica<br/>Arcilla<br/>Pizarra no metamórfica
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Minnesota
<br/><br/><label>Index Terms--Genre/Form: </label><br/>Libro
<br/><br/><label>Universal Decimal Class. No.: </label>553.61