Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
doi cua » dai cua, hoi cua
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ve tao » ve bao, de tao, ve tac
ma hoi » mai hoi, xa hoi, ma hoa
sai ky » sac ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sai ky)) nang ma hoi. hieu ve tao duoc ((van hanh) or (van thanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sai ky)) nang ma hoi. hieu ve tao duoc ((van hanh) OR (van thanh)) doi cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sai ky)) nang ma hoi. hieu ve tao duoc ((van hanh) or (van thanh)) doi cua tre*.