Relativism :
feet firmly planted in mid-air /
Francis J. Beckwith and Gregory Koukl.

APA Citation

Beckwith, F., Koukl, G. (1998). Relativism: feet firmly planted in mid-air. Grand Rapids, Mich.: Baker Books.

MLA Citation

Beckwith, Francis, and Gregory Koukl. Relativism: Feet Firmly Planted In Mid-air. Grand Rapids, Mich.: Baker Books, 1998.

Warning: These citations may not always be complete (especially for serials).