Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, can thuc, cay thuc
nam thuc » nam thuoc, am thuc, nam thu
manh hai » lanh hai, minh hai, thanh hai
cau treo » cau theo, cau tren, cau triet
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
va manh » van manh, va danh, va hanh
hai cau » hai chau, hai chu, hai hau

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 (nam thuc))) or (cam thu)) va manh 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 (nam thuc))) OR (cam thu)) va manh 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 (nam thuc))) or (cam thu)) va manh hai cau treo".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu van ((((cam thuc) OR (nam thuc))) or (cam thu)) va manh hai cau treo*.