Penfold, R.A. <br/><br/>
An introduction to QL machine code  [Books]. 
R.A.Penfold and J.W. Penfold. 
 - Shepherds Bush road, London  Bernard Babani Pub. Ltd.  1985 
 - Pages: 87. 
<br/><br/><label>ISBN: </label>0859341313  0.00 
<br/><br/><label>Subjects--Personal Names: </label><br/>Sinclair QL (Computer) -- Programming.
<br/><br/><label>Dewey Class. No.: </label>QA/76.8.S625  / PEN