APA
Bouwsma O. K., . (1965). Philosophical essays. Lincoln: University of Nebraska Press.
Chicago
Bouwsma O K, . 1965. Philosophical essays. Lincoln: University of Nebraska Press.
Harvard
Bouwsma O. K., . (1965). Philosophical essays. Lincoln: University of Nebraska Press.
MLA
Bouwsma O K, . Philosophical essays. Lincoln: University of Nebraska Press. 1965.