Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
vanh dai » van dai, vanh tai, lanh dao
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
truc va » thuc va, thuc vat, trung va
xuc va » duc va, tuc va, luc va
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky lang) or (ky tang)) xa hoi. hieu qua cham ((xuc va) or (truc va)) vanh dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky tang)) xa hoi. hieu qua cham ((xuc va) OR (truc va)) vanh dai cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky tang)) xa hoi. hieu qua cham ((xuc va) or (truc va)) vanh dai cua tu*.