Perhaps you should try some spelling variations:
thien van » thi van
thuc day » thuc dan
danh hai » dang hai, lanh hai, manh hai
cau treo » cau theo, cau tren, cau triet
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
hai cau » hai chau, hai chu, hai hau
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

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