Perhaps you should try some spelling variations:
dang than » dang thanh, sang than, dang tran
than cua » nhan cua, thai cua, ban cua
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
van bac » van ban, van hac, dan bac
van bao » van ban, van dao
va dang » van dang, va nang, va lang
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach ky) OR (sach ty)) nang x ho. thi ((van bac) or (van bao)) nuoc va dang than cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sach ky) OR (sach ty)) nang x ho. thi ((van bac) OR (van bao)) nuoc va dang than cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach ky) OR (sach ty)) nang x ho. thi ((van bac) or (van bao)) nuoc va dang than cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach ky) OR (sach ty)) nang x ho. thi ((van bac) or (van bao)) nuoc va dang than cua tre*.