Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
tan hanh » tan thanh, tang hanh, toan hanh
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, tu cach
te sach » toc sach
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
cuu tre » cua tre, cau tren, cau treo

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) or (te sach)) ky dang xa hoi. hieu van pham duc tan hanh vi ((cua viet) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky dang xa hoi. hieu van pham duc tan hanh vi ((cua viet) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky dang xa hoi. hieu van pham duc tan hanh vi ((cua viet) or (cuu tre))*.