Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dau tren » dau tien, dat tren, dau tieng
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, co hoi, cao hoc
cam tuc » cam tu, nam thuc, dam thuc
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dau
ca dau » ca dao, ca dan, va dau

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