Ryan, W.S. <br/><br/>
The increasing use of logical trees in the civil service 
by U.S. Ryan, VAC willis and P.W. Brook 
 - London  Her Majesty's Stationery Office  1970 
 - 20p. 
<br/><br/> CAS occasional paper/number-13 
<br/><br/><label>ISBN: </label>116300469 
<br/><br/><label>Dewey Class. No.: </label>K12x42 Un3in