Perhaps you should try some spelling variations:
dau thuc » dan thuc, dai thuc, dam thuc
thuc van » thuc vat, thuc dan, thuc va
thanh do » thanh de, thanh pho, thanh hoa
thanh di » thanh doi, thanh de, thanh dinh
su sach » so sach, vu sach
ly nang » ky nang, ly hang, ly vang
cuu tre » cua tre, cau tren, cau treo
va dau » va dao

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