Wagner, Percy Albert. <br/><br/>
The Pretoria salt-pan,  a soda caldera, 
by Percy A. Wagner ... 
 - Pretoria,  The Government Printing and Stationery Office,  1922. 
 - 136 p.  XIX pl. (part fold.; incl. fold. col. map) tables.  25 cm. 
 - South Africa. Geological Survey. Memoir  no. 20 .
<br/><br/> At head of title: Union of South Africa. Department of mines and industries. 
<br/><br/>Bibliographical foot-notes. 
<br/><br/><label>LCCN: </label>gs 23000005  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology, Economic--South Africa.<br/>Mines and mineral resources--South Africa.<br/>Salt mines and mining--South Africa.
<br/><br/><label>LC Class. No.: </label>QE324  / .A3 no. 20