APA
Sessions G., . (1995). Deep ecology for the twenty-first century. Boston: Shambhala.
Chicago
Sessions George, . 1995. Deep ecology for the twenty-first century. Boston: Shambhala.
Harvard
Sessions G., . (1995). Deep ecology for the twenty-first century. Boston: Shambhala.
MLA
Sessions George, . Deep ecology for the twenty-first century. Boston: Shambhala. 1995.