Lawden, D.F.. <br/><br/>
Introduction to Tensor Calculus, Relativity and Cosmology /  

 - 3rd Ed. /  
 - London :   John Wiley & Sons ,   1992 
 - p.205 :  
<br/><br/><label>ISBN: </label>0-471-10096-X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Relativity
<br/><br/><label>Dewey Class. No.: </label>CN  / K2