Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cau luc » cau truc, cau phuc
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
ve cau » ke cau, va cau, ve cac
sac ky » cac ky, sai ky
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 ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cau luc ((van hanh) or (van minh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cau luc ((van hanh) OR (van minh)) de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cau luc ((van hanh) or (van minh)) de cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sac ky)) nang ma hoi. hieu ve cau luc ((van hanh) or (van minh)) de cua tre*.