John Haskell, 'A Quarter Century of Direct Democracy in Presidential Nomination Campaigns: What's the Verdict?', in Robert DiClerico (ed.), Political Parties, Campaigns, and Elections, Prentice Hall, NJ, 2000, pp. 31–44.
انظر الانتخابات التمهيدية انظر الانتخابات التمهيدية الرئاسية في الولايات المتحدة John Haskell, 'A Quarter Century of Direct Democracy in Presidential Nomination Campaigns: What's the Verdict?', in Robert DiClerico (ed.), Political Parties, Campaigns, and Elections, Prentice Hall, NJ, 2000, pp. 31–44.