Perhaps you should try some spelling variations:
cham tuc » nham thuc, pham thuc, tham thuc
ban hanh » ban hang
su sach » so sach, vu sach
mai doi » moi doi, mai hoi, mai khoi
lai hoi » dai hoi, lai hoa, lai roi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
tuc ban » thuc ban, truc ban, tu ban
sach 6 » sach y, sach 2
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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 6 tang ((mai doi) or (lai hoi)). hieu va cham tuc ban hanh ((vi cua) OR (di cua)) vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach 6 tang ((mai doi) OR (lai hoi)). hieu va cham tuc ban hanh ((vi cua) OR (di cua)) vat*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach 6 tang ((mai doi) or (lai hoi)). hieu va cham tuc ban hanh ((vi cua) OR (di cua)) vat*".