Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
thuc day » thuc dan, thuc vat
hanh hai » thanh hai, nhanh hai, hang hai
cau treo » cau theo, cau tren, cau triet
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
thuc va » thuc vat, thuc dan
hai cau » hai chau, hai chu, hai hau
y nang » ky nang, ly nang, v nang

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 y nang cao hoi. ((hieu van) OR (lieu va)) nam ((thuc va) or (thuc day)) hanh hai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang cao hoi. ((hieu van) OR (lieu va)) nam ((thuc va) OR (thuc day)) hanh hai cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang cao hoi. ((hieu van) OR (lieu va)) nam ((thuc va) or (thuc day)) hanh hai cau treo".
• Adding a wildcard symbol may retrieve word variants: su sach y nang cao hoi. ((hieu van) OR (lieu va)) nam ((thuc va) or (thuc day)) hanh hai cau treo*.