ถนอมจิตศ์ ธ.; ช่วยบำรุง เ. A MODEL OF KNOWLEDGE ENHANCING OF THE YOUTHS IN SUKHOTHAI AND KAMPHAENG PHET PROVINCES BY MULTI-PARTY PARTICIPATION PROCESS TO PROMOTE WORLD HERITAGE TOURISM OF SUKHOTHAI HISTORICAL TOWN AND SURROUNDING TOWNS. spurhs 2018, 15, 35-45.