Perhaps you should try some spelling variations:
thien van » thi van
cau treo » cau theo, cau tren, cau triet
danh hai » dang hai, lanh hai, manh hai
thuc dan » thuc hanh, hoc dan, thuc vat
hai cau » hai chau, hai chu, hai hau
thuc va » thuc vat, thuc day
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
ma hoi » mai hoi, ma hoa, me hoi
van am » van nam, van lam, van dam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang ((ma hoi) OR (xa hoi)). thien van am ((thuc va) OR (thuc dan)) danh hai cau treo~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly nang ((ma hoi) or (xa hoi)). thien van am ((thuc va) OR (thuc dan)) danh hai cau treo~".
• Adding a wildcard symbol may retrieve word variants: su sach ly nang ((ma hoi) or (xa hoi)). thien van am ((thuc va) OR (thuc dan)) danh hai cau treo*.