Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cau luan » cu luan, dau luan, lau luan
cua tre » cua te, cuu tre, cua triet
hanh de » hanh ve, hanh kem
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
de cua » le cua, te cua, dieu cua
va cau » van cau, va cac, va dau
sac ky » cac ky
ma hoi » mai hoi, xa hoi, ma hoa

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 (sai ky))) or (sach y)) nang ma hoi. hieu va cau luan van hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((((sac ky) OR (sai ky))) OR (sach y)) nang ma hoi. hieu va cau luan van hanh de cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((((sac ky) OR (sai ky))) or (sach y)) nang ma hoi. hieu va cau luan van hanh de cua tre*".