Perhaps you should try some spelling variations:
tinh chuan » trinh chuan, tinh chua, tieu chuan
chat lanh » hat lanh, thuat lanh, nha lanh
canh tinh » hanh tinh, manh tinh, canh tranh
dong cong » duong cong, dung cong, cong cong
dang cong » dung cong
thang ban » hang ban, tang ban, thanh ban
hoc chat » hoc phat, hoc cao, hoc phan
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 chat lanh - canh tinh chuan ((dong cong) or (dang cong)) thang ban can~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chat lanh - canh tinh chuan ((dong cong) OR (dang cong)) thang ban can*.