Perhaps you should try some spelling variations:
cau treo » cau theo, cau tren, cau triet
hieu van » hieu va, thien van, lieu va
manh hai » lanh hai, minh hai, thanh hai
danh hai » dang hai, lanh hai, danh hau
cam tuc » cam xuc, cam tu, nam thuc
su sach » vu sach
nang ma » tang ma, sang ma, nang cao
so sach » so sanh, bo sach, co sach
van cam » van nam, van lam, van cau
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
y nang » ky nang, ly nang, v nang

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