Thwaites, F. T.  1883-1961. <br/><br/>
Educational collection of Wisconsin rocks, 
by Fredrik T. Thwaites. 
 - Madison, Wis.,  Published by the state,  1921. 
 - 33 p. incl. tables. 
 - Educational series  no. 7 .
<br/><br/><label>LCCN: </label>gs 33000403  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Rocks--Catalogs and collections.<br/>Petrology--Wisconsin.
<br/><br/><label>LC Class. No.: </label>QE179  / .A2 no. 63