FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "WPB." The Oxford Dictionary of Abbreviations. Oxford University Press. 1998. Encyclopedia.com. 10 Jul. 2009 <http://www.encyclopedia.com>.
FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "WPB." The Oxford Dictionary of Abbreviations. Oxford University Press. 1998. Encyclopedia.com. (July 10, 2009). http://www.encyclopedia.com/doc/1O25-WPB.html
FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "WPB." The Oxford Dictionary of Abbreviations. Oxford University Press. 1998. Retrieved July 10, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O25-WPB.html