Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
danh hai » dang hai, lanh hai, manh hai
ly quang » le quang, vu quang
cao hoi » cau hoi, co hoi, cao hoc
van cam » van lam, van cau, van dam
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
ly vang » ly hang, ly van
hai cau » hai chau, hai chu, hai hau
su sach » so sach, vu sach

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 vang) OR (ly quang)) cao hoi. hieu ((van cam) or (van nam)) truc va danh hai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly vang) OR (ly quang)) cao hoi. hieu ((van cam) OR (van nam)) truc va danh hai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ly vang) OR (ly quang)) cao hoi. hieu ((van cam) or (van nam)) truc va danh hai cau tren".
• Adding a wildcard symbol may retrieve word variants: su sach ((ly vang) OR (ly quang)) cao hoi. hieu ((van cam) or (van nam)) truc va danh hai cau tren*.