Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
danh di » danh du, xanh di, danh dien
danh vi » hanh vi, dinh vi, danh va
thuc va » thuc vat, thuc dan, thuc day
van cam » van nam, van lam, van cau
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
cua tre » cua te, cuu tre, cua triet

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 ((ty nang) OR (ty hang)) xa hoi. hieu van cam thuc va ((danh vi) or (danh di)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty nang) OR (ty hang)) xa hoi. hieu van cam thuc va ((danh vi) OR (danh di)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty nang) OR (ty hang)) xa hoi. hieu van cam thuc va ((danh vi) or (danh di)) cua tre*".