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

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 xuc va hanh vi ((dau tieng) or (ca 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 xuc va hanh vi ((dau tieng) OR (ca tren)).
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky sang) or (ky tang)) lai hoi. hieu van nam xuc va hanh vi ((dau tieng) or (ca tren))*.