There are two of them:

G. Tuchman (1972), "Objectivity as Strategic Ritual: An Examination of Newsmen’s Notions of Objectivity," American Journal of Sociology 77: 660–679 (recommended by Jay Rosen).

Henry Aaron, William Schwartz, and Melissa Cox (2005), Can We Say 'No'? the Challenge of Rationing Health Care (Washington: Brookings: 0815701217) http://www.amazon.com/exec/obidos/asin/0815701217/braddelong00.