Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
cuu tre » cua tre, cau treo
dau vat » dau va, bau vat, dan vat
cam duc » cam xuc, cao duc, pham duc
te sach » toc sach
ky dang » ky nang, ky danh
van cam » van nam, van lam, van cau
va dau » va dao
ky anh » ky danh, ly anh, ty anh

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 dang) or (ky anh)) xa hoi. hieu van cam duc va dau vat ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky dang) OR (ky anh)) xa hoi. hieu van cam duc va dau vat ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: te sach ((ky dang) or (ky anh)) xa hoi. hieu van cam duc va dau vat ((cuu tre) or (cau tren))*.