Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
lam thuc » lam thuoc, am thuc, nam thuc
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
ky dang » ky danh
van lam » van nam
va hanh » va thanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky dang) or (ky nang)) xa hoi. hieu van lam thuc ((va hanh) OR (van hanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky nang)) xa hoi. hieu van lam thuc ((va hanh) OR (van hanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky nang)) xa hoi. hieu van lam thuc ((va hanh) OR (van hanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky nang)) xa hoi. hieu van lam thuc ((va hanh) OR (van hanh)) di cua tre*.