Davis, Phil. <br/><br/>
Beyond the zone system. 

 - 3rd. 
 - Boston :  Focal Press,  c1993. 
<br/><br/><label>ISBN: </label>0240801938 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Photographic sensitometry.<br/>Zone system(photography).<br/>Photography -- Exposure.--Photography -- Exposure.