Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach ty, sach kem
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
ve cac » va cac, vien cac
va cam » va cham, va cac, va cao

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 (sach y)) nang ma hoa. hieu ((va cam) or (ve cac)) duc van hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang ma hoa. hieu ((va cam) OR (ve cac)) duc van hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) nang ma hoa. hieu ((va cam) or (ve cac)) duc van hanh dai cua tre*.