Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, hieu ve
van hanh » van thanh, ban hanh, van anh
kem phat » te phat, de phat, tam phat
te sach » toc sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
mai hoi » mai khoi, dai hoi, lai hoi
lam tuc » lam thuoc, lam truoc, luat tuc
va hanh » va thanh, va danh, ban hanh

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 ly nang mai hoi. ((hieu van) or (lieu va)) lam tuc ((va hanh) OR (van hanh)) kem phat trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly nang mai hoi. ((hieu van) OR (lieu va)) lam tuc ((va hanh) OR (van hanh)) kem phat trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly nang mai hoi. ((hieu van) or (lieu va)) lam tuc ((va hanh) OR (van hanh)) kem phat trien".
• Adding a wildcard symbol may retrieve word variants: te sach ly nang mai hoi. ((hieu van) or (lieu va)) lam tuc ((va hanh) OR (van hanh)) kem phat trien*.