Harker, Alfred,  1859-1939 <br/><br/>
Petrology for students :  an introduction to the study of rocks under the microscope / 
by Alfred Harker 
 - 6th ed. 
 - Cambridge :  The University Press,  1923 
 - 302 p. :  ill. ;  19 cm. 
 - Cambridge natural science manuals. [Geological series] .
<br/><br/> Includes index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Petrology