Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
doc sach » hoc sach, toc sach, nuoc sach
nam thuc » nam thuoc, am thuc, nam thu
thuc day » thuc dan, thuc vat
day hang » dat hang, dai hang, day nang
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hieu le » hieu ve, hieu he, hieu ly
hang di » hang doi, hang vi, hang dien
le nam » ly nam, he nam, le na
di cau » da cau, diem cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) or (so sach)) ky nang xa hoi. hieu le nam thuc day hang di cau triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (so sach)) ky nang xa hoi. hieu le nam thuc day hang di cau triet.
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (so sach)) ky nang xa hoi. hieu le nam thuc day hang di cau triet*.