Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
hanh ve » hanh vi, hanh va, hanh kem
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ty) or (sac ky)) nang xa hoi. ((hieu ve) or (hieu va)) cam duc van hanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sac ky)) nang xa hoi. ((hieu ve) OR (hieu va)) cam duc van hanh ve cua tre.
• Adding a wildcard symbol may retrieve word variants: toc ((sach ty) or (sac ky)) nang xa hoi. ((hieu ve) or (hieu va)) cam duc van hanh ve cua tre*.