Cahill Associates (2004), Darby Creek Watershed Conservation Plan(PDF), Darby Creek Valley Association, pp. 22, 76, 78, 80, archived from the original(PDF) on December 30, 2013, retrieved December 29, 2013
Cahill Associates (2004), Darby Creek Watershed Conservation Plan(PDF), Darby Creek Valley Association, pp. 22, 76, 78, 80, archived from the original(PDF) on December 30, 2013, retrieved December 29, 2013