Homan, Casey P., Marcus Mann, and Ryan T. Cragun. 2016. “United States of America: Secularist, Humanist, Atheist, and Freethought Bus Advertisements in the United States; Functions, Responses, and Effectiveness.” Pp. 369–94 in The Atheist Bus Campaign: Global Manifestations and Responses, edited by S. Tomlins and S. Bullivant. Leiden ; Boston: Brill Academic Pub.
This book chapter can be downloaded here.