Perhaps you should try some spelling variations:
thien van » thi van
cau treo » cau theo, cau tren, cau triet
manh hai » lanh hai, minh hai, thanh hai
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, lieu va, hieu ve
hai cau » hai chau, hai chu, hai hau
va manh » van manh, va danh, va hanh
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach lo, sach ty, sach hay
nang ma » tang ma, sang ma, nang cao
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 ly) or (sach y)) nang ma hoi. ((hieu van) OR (thien van)) cam thuc va manh hai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ly) OR (sach y)) nang ma hoi. ((hieu van) OR (thien van)) cam thuc va manh hai cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ly) or (sach y)) nang ma hoi. ((hieu van) OR (thien van)) cam thuc va manh hai cau treo".
• Adding a wildcard symbol may retrieve word variants: su ((sach ly) or (sach y)) nang ma hoi. ((hieu van) OR (thien van)) cam thuc va manh hai cau treo*.