Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
cau luan » cu luan, dau luan, lau luan
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
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 y)) nang ma hoi. hieu va cau luan ((van hanh) OR (van thanh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sach y)) nang ma hoi. hieu va cau luan ((van hanh) OR (van thanh)) de cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) or (sach y)) nang ma hoi. hieu va cau luan ((van hanh) OR (van thanh)) de cua tre*".