Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dau tren » dau tien, dat tren, dau tieng
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, ca tren, cau treo
ky tang » ky nang, ky dang, kho tang
lai hoi » dai hoi, lai hoa, lai roi
nam tuc » nam thuc, nam truc, nam tu
va hanh » van hanh, va thanh, va danh
ky sang » ky nang, ky dang, duy sang
tuc va » thuc va, truc va, tuc xa

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 ((ky sang) or (ky tang)) lai hoi. hieu van nam tuc va hanh vi ((dau tren) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky sang) OR (ky tang)) lai hoi. hieu van nam tuc va hanh vi ((dau tren) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky sang) or (ky tang)) lai hoi. hieu van nam tuc va hanh vi ((dau tren) or (cau tren))*.