Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
cua tre » cua te, cua triet, dua tren
hanh de » hanh ve, hanh kem
cuu tre » cau tren, cau treo
hau duc » huu duc, ha duc, phan duc
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang

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 y nang xa hoi. hieu van ((hau duc) OR (pham duc)) van hanh de ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang xa hoi. hieu van ((hau duc) OR (pham duc)) van hanh de ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang xa hoi. hieu van ((hau duc) OR (pham duc)) van hanh de ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: te sach y nang xa hoi. hieu van ((hau duc) OR (pham duc)) van hanh de ((cua tre) or (cuu tre))*.