Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
thuc day » thuc dan, thuc vat
day hang » dat hang, dai hang, day nang
su sach » vu sach
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
hang di » hang doi, hang vi, hang dien
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
di cua » dai cua, doi cua, de cua

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 xa hoi. hieu ve cam thuc day hang di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y nang xa hoi. hieu ve cam thuc day hang di cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) y nang xa hoi. hieu ve cam thuc day hang di cua tre*.