Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cham tuc » nham thuc, pham thuc, tham thuc
hieu va » lieu va, hieu qua
tu sach » thu sach, te sach, tu cach
cao hoi » cau hoi, co hoi, cao hoc
su sach » so sach, vu sach
va cham » va chat, va tham
va dan » va dao, va dau, va dap
ca dan » cac dan, ca dao
ca cau » cua cau, cac cau, can cau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang cao hoi. hieu va cham tuc ((va dan) OR (ca dan)) ca cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang cao hoi. hieu va cham tuc ((va dan) OR (ca dan)) ca cau tren~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang cao hoi. hieu va cham tuc ((va dan) OR (ca dan)) ca cau tren*.