Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
tu sach » thu sach, su sach, te sach
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duc van » duc va, duc manh, duc phan
hai cua » thai cua, dai cua, hoi cua
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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) or (so sach)) ky nang o hoi. hieu ve pham ((duc van) OR (duc tan)) thanh hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (so sach)) ky nang o hoi. hieu ve pham ((duc van) OR (duc tan)) thanh hai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (so sach)) ky nang o hoi. hieu ve pham ((duc van) OR (duc tan)) thanh hai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (so sach)) ky nang o hoi. hieu ve pham ((duc van) OR (duc tan)) thanh hai cua te*.