APA
Fisher Roger,, . (1991). Getting to yes negotiating : Agreement without giving in. London: Penguin Books.
Chicago
Fisher Roger,, . 1991. Getting to yes negotiating : Agreement without giving in. London: Penguin Books.
Harvard
Fisher Roger,, . (1991). Getting to yes negotiating : Agreement without giving in. London: Penguin Books.
MLA
Fisher Roger,, . Getting to yes negotiating : Agreement without giving in. London: Penguin Books. 1991.