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. 1 Dec. 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. (December 1, 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 December 01, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O25-WPB.html