Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hieu van » thien van, lieu va, hieu ve
nhan luc » nang luc
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
tu cai » tu cac, tu can, tu bai
cai ky » cao ky, cac ky, cam ky
luc va » duc va, tuc va, loc va
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 cai ky nang mai hoi. ((hieu van) OR (hieu va)) nhan luc va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cai ky nang mai hoi. ((hieu van) OR (hieu va)) nhan luc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu cai ky nang mai hoi. ((hieu van) OR (hieu va)) nhan luc va hanh vi cua tre*.