Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
dang hai » dang khai, hang hai, dung hai
day dang » da dang, dai dang, day dan
thuc day » thuc dan, thuc vat
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, hieu ve
nang ma » tang ma, sang ma, nang cao
vu sach » vu bach, vu khach
hai cau » hai chau, hai chu, hai hau
su sach » so sach
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) OR (vu sach)) ky nang ma hoi. ((hieu van) or (lieu va)) cam thuc day dang hai cau triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang ma hoi. ((hieu van) OR (lieu va)) cam thuc day dang hai cau triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ky nang ma hoi. ((hieu van) or (lieu va)) cam thuc day dang hai cau triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ky nang ma hoi. ((hieu van) or (lieu va)) cam thuc day dang hai cau triet*.