APA
Kierkegaard S., Steere D. V., . (1948). Purity of heart is to will one thing. New York: Harper.
Chicago
Kierkegaard Sr̜en, Steere Douglas V, . 1948. Purity of heart is to will one thing. New York: Harper.
Harvard
Kierkegaard S., Steere D. V., . (1948). Purity of heart is to will one thing. New York: Harper.
MLA
Kierkegaard Sr̜en, Steere Douglas V, . Purity of heart is to will one thing. New York: Harper. 1948.