International Council for Correspondence Education. World Conference & Wentworth, R. B. (1978). Correspondence education, dynamic and diversified: Eleventh World Conference, Hotel Ashoka, New Delhi, India, 8-15 November 1978. s.n..
Lua i Stíl Chicago (17ú heag.)International Council for Correspondence Education. World Conference agus Robert B. Wentworth. Correspondence Education, Dynamic and Diversified: Eleventh World Conference, Hotel Ashoka, New Delhi, India, 8-15 November 1978. [s.l.: s.n., 1978.
Lua MLA (8ú heag.)International Council for Correspondence Education. World Conference agus Robert B. Wentworth. Correspondence Education, Dynamic and Diversified: Eleventh World Conference, Hotel Ashoka, New Delhi, India, 8-15 November 1978. s.n., 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.