Harker, Alfred. <br/><br/>
Petrology for students :  an introduction to the study of rocks under the microscope / 
by Alfred Harker. 
 - 5th ed. 
 - Cambridge, UK :  The University Press,  1919. 
 - 300 p. :  ill. ;  19 cm. 
 - Cambridge geological series .
<br/><br/> Includes index. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Petrology--Study and teaching (Higher).<br/>Petrology.