The Compass to Nature: Teaching in the Outdoor Classroom
https://www.fws.gov/uploadedFiles/Compass%20to%20Nature%20FINAL%20low%20resolution.pdf
Field Investigations Using Outdoor Environments to Foster Student Learning of Scientific Practices
https://www.fishwildlife.org/application/files/3915/1373/0920/ConEd-2015-Revision-Field_Investigations_.pdf