Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nam mua » nam cua, nam qua, nam xua
mua ban » cua ban, qua ban
vai cau » va cau, vai cac, lai chau
van cau » van dau, van hau, van chat
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang ((ma hoi) or (ma hoa)). hieu van nam mua ban thanh ((vai cau) OR (van cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((ma hoi) OR (ma hoa)). hieu van nam mua ban thanh ((vai cau) OR (van cau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang ((ma hoi) or (ma hoa)). hieu van nam mua ban thanh ((vai cau) OR (van cau)) treo".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ((ma hoi) or (ma hoa)). hieu van nam mua ban thanh ((vai cau) OR (van cau)) treo*.