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