Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, co hoi, tao hoi
cao hoc » co hoc, cho hoc, chat hoc
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
ca cau » cua cau, cac cau, can cau

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 y nang ((cao hoi) or (cao hoc)). hieu ve cac tuc va dan ca cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((cao hoi) OR (cao hoc)). hieu ve cac tuc va dan ca cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((cao hoi) or (cao hoc)). hieu ve cac tuc va dan ca cau tren*.