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

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