Perhaps you should try some spelling variations:
vanh tai » van tai, hanh tai, anh tai
thi nang » thi cong, ki nang, thi hanh
so sach » bo sach, co sach, hoc sach
tai cua » thai cua, tai cuc, tri cua
chuc va » thuc va
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
nang co » nang cao, nang doc, nang noi
so sanh » do sanh
co hoi » co hoc, co loi
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: ((so sach) or (so sanh)) thi nang co hoi. hieu va pham ((chuc va) OR (thuc vat)) vanh tai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) thi nang co hoi. hieu va pham ((chuc va) OR (thuc vat)) vanh tai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (so sanh)) thi nang co hoi. hieu va pham ((chuc va) OR (thuc vat)) vanh tai cua tu".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) thi nang co hoi. hieu va pham ((chuc va) OR (thuc vat)) vanh tai cua tu*.