Heuser, Martha, Erin Nowak, and Tiffany Thurman. “Sustaining Sustainability: Interview With Katherine Gajewski, Director of Sustainability, City of Philadelphia”. Social Innovations Journal, no. 15 (November 1, 2013). Accessed May 12, 2026. https://socialinnovationsjournal.com/index.php/sij/article/view/10620.