Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang thai » dang thi, dang khai, lang thai
dang hai » dang khai, hang hai, dung hai
sach ky » sac ky, sach y, sach ty
van bac » van ban, van bao, dan bac
van hac » van hoc, van ha, van hai
cua tre » cua te, cuu tre, cua triet
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: thuoc sach ky nang x hoi. thi ((van bac) or (van hac)) nuoc va ((dang thai) OR (dang hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky nang x hoi. thi ((van bac) OR (van hac)) nuoc va ((dang thai) OR (dang hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky nang x hoi. thi ((van bac) or (van hac)) nuoc va ((dang thai) OR (dang hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky nang x hoi. thi ((van bac) or (van hac)) nuoc va ((dang thai) OR (dang hai)) cua tre*.