FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "HOLC." The Oxford Dictionary of Abbreviations. 1998. Encyclopedia.com. 10 Feb. 2010 <http://www.encyclopedia.com>.
FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "HOLC." The Oxford Dictionary of Abbreviations. 1998. Encyclopedia.com. (February 10, 2010). http://www.encyclopedia.com/doc/1O25-HOLC.html
FRAN ALEXANDER , PETER BLAIR , JOHN DAINTITH , ALICE GRANDISON , VALERIE ILLINGWORTH , ELIZABETH MARTIN , ANNE STIBBS , JUDY PEARSALL , and SARA TULLOCH. "HOLC." The Oxford Dictionary of Abbreviations. 1998. Retrieved February 10, 2010 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O25-HOLC.html