Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
trung va » truong va, trang va, trung ha
danh sai » dung sai, danh bat, danh dau
ky lang » ky dang, ky tang, tay lang
van cac » van hac, van cau, van bac
van hoc » van hoa
va danh » va dinh, va dan, va hanh
sai cua » dai cua, hai cua, lai cua
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: thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) or (van hoc)) trung va danh sai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) OR (van hoc)) trung va danh sai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) or (van hoc)) trung va danh sai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky lang) OR (ky nang)) xa hoi. hieu ((van cac) or (van hoc)) trung va danh sai cua tre*.