Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
van hanh » van thanh, ban hanh, van ban
sach ty » sach y, sach tu, xach tay
xang xa » lang xa, mang xa, ang xa
van anh » van thanh, tuan anh, van minh
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) or (sach thu)) xang xa hoi. lieu va cau truc ((van hanh) OR (van anh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) xang xa hoi. lieu va cau truc ((van hanh) OR (van anh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach thu)) xang xa hoi. lieu va cau truc ((van hanh) OR (van anh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach thu)) xang xa hoi. lieu va cau truc ((van hanh) OR (van anh)) vi cua tre*.