Perhaps you should try some spelling variations:
quang luan » quang tuan, quang uan, quang xuan
hieu soat » hieu suat, hieu hoat, kiem soat
hieu luat » hieu qua
minh tuan » anh tuan
tuan quan » toan quan, quan quan, tran quang
luan kien » xuan kien, luan lien, quan kien
kien soat » kiem soat, bien soan, kien hoa
tinh » trinh, dinh, kinh

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quang luan van ((hieu soat) OR (hieu luat)) ) OR ( minh tuan quan luan kien soat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh quang luan van ((hieu soat) OR (hieu luat)) ) or ( minh tuan quan luan kien soat ))~".
• Adding a wildcard symbol may retrieve word variants: (( tinh quang luan van ((hieu soat) OR (hieu luat)) ) or ( minh tuan quan luan kien soat ))*.