Perhaps you should try some spelling variations:
thanh lai » thanh hai, thanh lap, thanh loi
duc manh » suc manh, duc anh, duc minh
tu sach » thu sach, te sach, tu cach
lai cua » dai cua, hai cua, lai chau
duc van » duc va, duc tan, duc phan
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
ve cam » ve cham, ve cac, va cam
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 (su sach)) ky nang o hoi. hieu ve cam ((duc van) OR (duc manh)) thanh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang o hoi. hieu ve cam ((duc van) OR (duc manh)) thanh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang o hoi. hieu ve cam ((duc van) OR (duc manh)) thanh lai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang o hoi. hieu ve cam ((duc van) OR (duc manh)) thanh lai cua te*.