Perhaps you should try some spelling variations:
khoi thuat » ki thuat, hoc thuat
thuat tach » thuat sach, thuat mach, thuat tac
trung quan » truong quan, trong quan, trung tuan
trong tac » trong cac, tuong tac, trong tan
tung qua » dung qua, tuong quan, duong qua
tac than » tac thanh, tam than, tac nhan
than cao » toan cao, thai cao, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: khoi thuat tach - thanh ((tung qua) or (trung quan)) dung trong tac than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: khoi thuat tach - thanh ((tung qua) OR (trung quan)) dung trong tac than cao.
• Adding a wildcard symbol may retrieve word variants: khoi thuat tach - thanh ((tung qua) or (trung quan)) dung trong tac than cao*.