Perhaps you should try some spelling variations:
te sach » toc sach
va danh » va dinh, va dan, va hanh
cau luc » cau truc, cau phuc
sach ky » sac ky, sach y, sach ty
hieu ke » hieu kem, chieu ke, hieu ky
luc va » duc va, tuc va, loc va
co hoi » co hoc, co loi
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu cua
ke cau » ket cau
o hoi » o hoc, o hai, o hoa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ((co hoi) or (o hoi)). hieu ke cau luc va danh ((di cua) OR (de cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((co hoi) OR (o hoi)). hieu ke cau luc va danh ((di cua) OR (de cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((co hoi) or (o hoi)). hieu ke cau luc va danh ((di cua) OR (de cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((co hoi) or (o hoi)). hieu ke cau luc va danh ((di cua) OR (de cua)) tre*.