Perhaps you should try some spelling variations:
sach ky » sac ky, sach ty, sach kem
hieu ve » hieu va, hieu van
duc ban » duc tan, duc van, dua ban
hanh ve » hanh vi, hanh va, hanh kem
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
ve cua » le cua, de cua, te cua
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu ve cam ((cua ban) or (duc ban)) hanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang x hoi. hieu ve cam ((cua ban) OR (duc ban)) hanh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sach y)) nang x hoi. hieu ve cam ((cua ban) or (duc ban)) hanh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sach y)) nang x hoi. hieu ve cam ((cua ban) or (duc ban)) hanh ve cua tre*.