O'Kelly, M., Ryan-Enright, M., & Whelan, D. (1988). Discover our world: Environmental studies; nature, civics, science. Folens.
Citazione stile Chigago Style (17a edizione)O'Kelly, Mary, Mary Ryan-Enright, e Deirdre Whelan. Discover Our World: Environmental Studies; Nature, Civics, Science. Dublin: Folens, 1988.
Citatione MLA (9a ed.)O'Kelly, Mary, et al. Discover Our World: Environmental Studies; Nature, Civics, Science. Folens, 1988.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.