Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van dinh » van dich, va dinh, xuan dinh
sinh cua » manh cua, dinh cuu, sinh va
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
nam xua » nam cua, nam mua, nam qua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cac) or (tu sach)) ky nang xa hoi. hieu van nam xua ((van dinh) OR (van minh)) sinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cac) OR (tu sach)) ky nang xa hoi. hieu van nam xua ((van dinh) OR (van minh)) sinh cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cac) or (tu sach)) ky nang xa hoi. hieu van nam xua ((van dinh) OR (van minh)) sinh cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cac) or (tu sach)) ky nang xa hoi. hieu van nam xua ((van dinh) OR (van minh)) sinh cua tre*.