Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
nam qua » nam quan, nam cua, nam mua
qua van » quan van, qua ban, qua san
cua tre » cua te, cuu tre, cua triet
tu sac » tu cac, tu san, tu bac
vi cua » vai cua, di cua

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

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