Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
thu nang » thi nang, thu hang, thu bang
thuc van » thuc vat, thuc dan, thuc va
chuc van » chu van, chuc va, chuc can
so sach » bo sach, co sach, hoc sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
cao hoi » cau hoi, co hoi, cao hoc
so sanh » do sanh
cua te » cua tu

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)) thu nang cao hoi. hieu ve pham ((chuc van) OR (thuc van)) hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) thu nang cao hoi. hieu ve pham ((chuc van) OR (thuc van)) hanh dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (so sanh)) thu nang cao hoi. hieu ve pham ((chuc van) OR (thuc van)) hanh dai cua te".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) thu nang cao hoi. hieu ve pham ((chuc van) OR (thuc van)) hanh dai cua te*.