Fisher, Roger 1922-.
Getting to yes : negotiating agreement without giving in /
Roger Fisher and William Ury ; Bruce Patton, editor 
. - 2nd edition 
. - New York : Penguin Books,  1991 
. - xix, 200 p.  tabl.  22 cm. 
<br/><label>  ISBN: </label>0-14-015735-2