Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hang truc » khung truc
nang mai » nang ma, nang tai, lang mai
hieu van » thien van, lieu va, hieu ve
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
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: su sach ky nang mai hoi. ((hieu van) OR (hieu va)) hang truc ((va hanh) or (van thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang mai hoi. ((hieu van) OR (hieu va)) hang truc ((va hanh) OR (van thanh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang mai hoi. ((hieu van) OR (hieu va)) hang truc ((va hanh) or (van thanh)) vi cua tre*".