Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
luoc van » luoc can, luoc va, luc van
cau luoc » cau luc, muu luoc, hau loc
cua tre » cua te, cuu tre, cua triet
hanh de » hanh ve, hanh kem
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, mang may
sach ty » sach y, sach tu, sach thu
sac ky » cac ky, sai ky
va cau » van cau, va cac, va dau
de cua » le cua, te cua, dieu cua

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

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