Martin, Helen M.  1889-1973. <br/><br/>
Outline of the geologic history of Hillsdale County, 
by Helen M. Martin. 
 - [Lansing,  Michigan Dept. of Conservation, Geological Survey Division,  1957] 
 - 11 l.  maps, diagrs. 
<br/><br/><label>LCCN: </label>gs 58000148  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology--Michigan--Hillsdale County.
<br/><br/><label>LC Class. No.: </label>QE126.H5  / M3