Perhaps you should try some spelling variations:
vanh dai » vanh tai, lanh dao, van dao
so sach » so sanh, bo sach, co sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
qua hai » qua hoat
van dai » van dao, van hai, can dai
hai xu » thai xu, hai vu, dai xu
cua te » cua tu
xu va » xu van, tu va, su va

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

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