"Roster of Sierra Club Directors"(PDF). Archived from the original(PDF) on 2013-07-04. Retrieved 2014-03-17. Roster of Sierra Club Directors, Sierra Club, San Francisco, May 18, 2010
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"Roster of Sierra Club Directors"(PDF). Archived from the original(PDF) on 2013-07-04. Retrieved 2014-03-17. Roster of Sierra Club Directors, Sierra Club, San Francisco, May 18, 2010