User contributions
- 10:37, 1 April 2013 (diff | hist) . . (+14) . . 1193: Externalities (→Second Panel: correction)
- 10:30, 1 April 2013 (diff | hist) . . (+1) . . 1193: Externalities (→Explanation)
- 10:30, 1 April 2013 (diff | hist) . . (+13) . . 1193: Externalities (→Explanation: new wikipedia article is being used.)
- 10:25, 1 April 2013 (diff | hist) . . (+12) . . 1193: Externalities (→Explanation)