APA
Gilkey L., . (1979). Message and existence. San Francisco: Harper and Row Publishers.
Chicago
Gilkey Langdon, . 1979. Message and existence. San Francisco: Harper and Row Publishers.
Harvard
Gilkey L., . (1979). Message and existence. San Francisco: Harper and Row Publishers.
MLA
Gilkey Langdon, . Message and existence. San Francisco: Harper and Row Publishers. 1979.