Perhaps you should try some spelling variations:
cau treo » cau theo, cau tren, cau triet
hieu van » hieu va, thien van, lieu va
minh hai » minh khai, tinh hai, minh chau
cam thuc » am thuc, nam thuc, can thuc
manh hai » lanh hai, thanh hai, van hai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cam thu » nam thu, cac thu, ca thu

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