Perhaps you should try some spelling variations:
cau treo » cau theo, cau tren, cau triet
cam thuc » am thuc, nam thuc, cam thu
hang hai » hoang hai, hang tai, thanh hai
manh hai » lanh hai, minh hai, thanh hai
thuc day » thuc dan, thuc vat
hieu van » hieu va, thien van, lieu va
sach ty » sach tu, sach thu, xach tay
nang ma » tang ma, sang ma, nang cao
van cam » van nam, van lam, van cau
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 ty) or (sach y)) nang ma hoi. hieu van cam thuc day ((manh hai) or (hang hai)) cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang ma hoi. hieu van cam thuc day ((manh hai) OR (hang hai)) cau treo.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) nang ma hoi. hieu van cam thuc day ((manh hai) or (hang hai)) cau treo*.