Christie, L. (1987). Unsung heroes: How to recruit and train volunteer youth workers. Zondervan.
Lua i Stíl Chicago (17ú heag.)Christie, Les. Unsung Heroes: How to Recruit and Train Volunteer Youth Workers. Grand Rapids: Zondervan, 1987.
Lua MLA (9ú heag.)Christie, Les. Unsung Heroes: How to Recruit and Train Volunteer Youth Workers. Zondervan, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.