Perhaps you should try some spelling variations:
te sach » toc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi
ve cac » va cac, vien cac
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
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 ((o hoi) OR (co hoi)). hieu ve cac tuc va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((o hoi) OR (co hoi)). hieu ve cac tuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((o hoi) OR (co hoi)). hieu ve cac tuc va hanh vi cua tre*.