Perhaps you should try some spelling variations:
cau treo » cau theo, cau tren, cau triet
manh hai » lanh hai, minh hai, thanh hai
nam thuc » nam thuoc, am thuc, nam thu
cam thuc » am thuc, cam thu, can thuc
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
sach ly » sach y, sach lo, sach ty
nang xa » nang x, lang xa, mang xa
va manh » van manh, va danh, va hanh
hai cau » hai chau, hai chu, hai hau
so sach » so sanh, bo sach, co sach

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: so sach ly ((nang xa) OR (nang ma)) hoi. hieu van ((cam thuc) OR (nam thuc)) va manh hai cau treo~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ly ((nang xa) OR (nang ma)) hoi. hieu van ((cam thuc) or (nam thuc)) va manh hai cau treo~".
• Adding a wildcard symbol may retrieve word variants: so sach ly ((nang xa) OR (nang ma)) hoi. hieu van ((cam thuc) or (nam thuc)) va manh hai cau treo*.