What are the dates of publications in descending order of price?
SELECT Publication_Date FROM publication ORDER BY Price DESC
SELECT Publication_Date FROM publication ORDER BY Price DESC
[{'Publication_Date': 'August 2008'}, {'Publication_Date': 'March 2008'}, {'Publication_Date': 'June 2006'}, {'Publication_Date': 'October 2005'}, {'Publication_Date': 'August 2008'}, {'Publication_Date': 'March 2007'}, {'Publication_Date': 'April 2007'}]