Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duc van » duc va, duc tan, duc manh
lap cua » tap cua, lam cua, ap cua
lai cua » dai cua, hai cua, lai chau
nang o » nang co, nang ho, nang ro
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: ((thu sach) or (co sach)) ky nang o hoi. hieu ve pham duc van thanh ((lap cua) OR (lai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (co sach)) ky nang o hoi. hieu ve pham duc van thanh ((lap cua) OR (lai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (co sach)) ky nang o hoi. hieu ve pham duc van thanh ((lap cua) OR (lai cua)) te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (co sach)) ky nang o hoi. hieu ve pham duc van thanh ((lap cua) OR (lai cua)) te*.