Owyatchara Sayuen และ Prayong Klanrit. (2554) A Comparison of Students’ English Speaking Proficiency Using Communicative Tasks of Mattayomsuksa 6 Students in Nongbuapittayakarn School, Nongbua Lamphu. Udon Thani Rajabhat University:ม.ป.ท.Owyatchara Sayuen และ Prayong Klanrit. 2554. A Comparison of Students’ English Speaking Proficiency Using Communicative Tasks of Mattayomsuksa 6 Students in Nongbuapittayakarn School, Nongbua Lamphu. ม.ป.ท.:Udon Thani Rajabhat University;Owyatchara Sayuen และ Prayong Klanrit. A Comparison of Students’ English Speaking Proficiency Using Communicative Tasks of Mattayomsuksa 6 Students in Nongbuapittayakarn School, Nongbua Lamphu. ม.ป.ท.:Udon Thani Rajabhat University, 2554. Print.