Bargen Biles( 2001): Activates that Promote Racial and Cultural Awareness in Pre-School University of Illinois,p34.
Gary Homana et.al., School Citizenship Education Climate Assessment, University of Maryland, College Park, April 2005, p.6.
Krejcie& Morgan in their. (1970). article “Determining Sample Size for Research Activities” (Educational and Psychological Measurement, #30, pp. 607-610).
Paula Olszewski-Kubilius, and Sean-young Lee," The Role of Participation in in-School and outside-of-School Activities in The Talent Development of Gifted Students", The Journal of Secondary Gifted Education, Vol. XV, No.3, Spring 2004, pp. 107, 109.
The Encyclopedia of Education: Sports Activities for Men, U.S.A. the Free Press, vol.8, 2002, P.489.