Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
dat duoc » dat nuoc, da duoc, luat duoc
cua tre » cua te, cuu tre, cua triet
va hanh » va thanh, va danh, ban hanh
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sac ky » cac ky, sai ky
ve dat » de dat, va dat, ve dao
vi cua » vai cua, di cua
vu sac » vu sach, vu san, va sac

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky ((nang ma) or (tang ma)) hoi. hieu ve dat duoc ((va hanh) OR (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky ((nang ma) OR (tang ma)) hoi. hieu ve dat duoc ((va hanh) OR (van hanh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sac ky ((nang ma) or (tang ma)) hoi. hieu ve dat duoc ((va hanh) OR (van hanh)) vi cua tre*".