Perhaps you should try some spelling variations:
thuong cong » thong cong, thuong con, thuong dong
thanh thang » nhanh thang, thanh thanh, thanh hang
hieu cach » hieu cac, chieu sach, biet cach
toan phan » thanh phan, toan ban, hoa phan
thang va » hang va, trang va, thong va
tan phan » than phan, van phan, tai phan
hieu ca » hieu cac, hieu cua, hieu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu cach) OR (hieu ca)) - thanh thang va thuong cong ((tan phan) or (toan phan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu cach) OR (hieu ca)) - thanh thang va thuong cong ((tan phan) OR (toan phan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu cach) OR (hieu ca)) - thanh thang va thuong cong ((tan phan) or (toan phan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu cach) OR (hieu ca)) - thanh thang va thuong cong ((tan phan) or (toan phan)) cau*.