Perhaps you should try some spelling variations:
gian cua » gian xu, ban cua
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
van dan » ban dan, van dao, van dau
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
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: thu ((sach ky) or (sac ky)) nang x hoi. hieu ve cac duc ((van dan) OR (van ban)) gian cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang x hoi. hieu ve cac duc ((van dan) OR (van ban)) gian cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sac ky)) nang x hoi. hieu ve cac duc ((van dan) OR (van ban)) gian cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sac ky)) nang x hoi. hieu ve cac duc ((van dan) OR (van ban)) gian cua tre*.