Perhaps you should try some spelling variations:
dat thanh » dao thanh, dat khanh, dang thanh
cam thuc » am thuc, nam thuc, can thuc
ban hang » ngan hang
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cam thu » nam thu, cac thu, ca thu
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu ve ((cam thuc) OR (cam thu)) ((dat thanh) or (ban hang)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu ve ((cam thuc) OR (cam thu)) ((dat thanh) OR (ban hang)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu ve ((cam thuc) OR (cam thu)) ((dat thanh) or (ban hang)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu ve ((cam thuc) OR (cam thu)) ((dat thanh) or (ban hang)) di cua tre*.