Hungerford, H. R., & Litherland, R. A. (1975). Teacher's Guide to Modules 1, 2, 3, 4, and 5 of the Process Modules for Investigating Environmental Problems.
Citazione stile Chigago Style (17a edizione)Hungerford, Harold R., e Ralph A. Litherland. Teacher's Guide to Modules 1, 2, 3, 4, and 5 of the Process Modules for Investigating Environmental Problems. 1975.
Citatione MLA (9a ed.)Hungerford, Harold R., e Ralph A. Litherland. Teacher's Guide to Modules 1, 2, 3, 4, and 5 of the Process Modules for Investigating Environmental Problems. 1975.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.