Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
ban thanh » ban hanh, ban hang
thanh vi » hanh vi, thanh va, thanh ve
thuc ban » thuoc ban, thuc dan, thu ban
su sach » vu sach
so sach » so sanh, bo sach, co sach
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
va cham » va chat, va tham
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (so sach)) ty ((hang va) or (tang ma)) hoi. hieu va cham thuc ban thanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ty ((hang va) OR (tang ma)) hoi. hieu va cham thuc ban thanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ty ((hang va) or (tang ma)) hoi. hieu va cham thuc ban thanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) ty ((hang va) or (tang ma)) hoi. hieu va cham thuc ban thanh vi cua te*.