Perhaps you should try some spelling variations:
quang phap » quang phat, quan phap, quang phan
thieu qua » hieu qua, thieu cua, thieu quang
trinh tac » trinh tai, trinh tam, trinh cac
tac quang » thac quang, tac quan, tai quang
tieng han » tieng anh
tin tung » tien tung, tin tuong, tin dung
tung dan » dung dan, huong dan, trung dai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin tung dan toc thieu qua ) or ( trinh tac quang phap tieng han ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin tung dan toc thieu qua ) OR ( trinh tac quang phap tieng han )).
• Adding a wildcard symbol may retrieve word variants: (( tin tung dan toc thieu qua ) or ( trinh tac quang phap tieng han ))*.