Perhaps you should try some spelling variations:
hoc thuat » hoc thuyet, hoc thuc, hoc chat
thuat lap » thuat lanh, thuat xay, thuat bai
canh tieu » cach tieu, dinh tieu, hang tieu
dong cong » duong cong, dung cong, cong cong
dang cong » dung cong
thang ban » hang ban, tang ban, thanh ban
ban can » ban dan, ban hang, ban hanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thuat lap - canh tieu chuan ((dong cong) or (dang cong)) thang ban can~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thuat lap - canh tieu chuan ((dong cong) OR (dang cong)) thang ban can.
• Adding a wildcard symbol may retrieve word variants: hoc thuat lap - canh tieu chuan ((dong cong) or (dang cong)) thang ban can*.