Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hang vai » hang va, hang tai, hang hai
luan ban » luan van, luan san, luan han
lua ban » luat ban, cua ban, qua ban
vai cua » dai cua, hai cua, lai cua
hieu va » lieu va, hieu qua
va cay » va cac, va cao, va cai
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, me hoi
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: thu sach y nang ((ma hoi) or (ma hoa)). hieu va cay ((lua ban) OR (luan ban)) hang vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((ma hoi) OR (ma hoa)). hieu va cay ((lua ban) OR (luan ban)) hang vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang ((ma hoi) or (ma hoa)). hieu va cay ((lua ban) OR (luan ban)) hang vai cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ((ma hoi) or (ma hoa)). hieu va cay ((lua ban) OR (luan ban)) hang vai cua te*.