Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
dang cac » dung cac, bang cac, dong cac
cac cau » cac mau, bac cau, ca cau
ca dang » cao dang, cua dang, cac dang
cam tuc » cam tu, nam thuc, dam thuc
so sach » so sanh, bo sach, co sach
cao hoi » cau hoi, co hoi, cao hoc
te sach » toc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) or (te sach)) ky nang cao hoi. hieu van ((cam tuc) or (cam xuc)) ca dang cac cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (te sach)) ky nang cao hoi. hieu van ((cam tuc) OR (cam xuc)) ca dang cac cau tren.
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (te sach)) ky nang cao hoi. hieu van ((cam tuc) or (cam xuc)) ca dang cac cau tren*.