Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
ha hoi » hoa hoi, ha noi, va hoi
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky lang ((ha hoi) or (xa hoi)). hieu ve nam thuc va thanh vi ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((ha hoi) OR (xa hoi)). hieu ve nam thuc va thanh vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((ha hoi) or (xa hoi)). hieu ve nam thuc va thanh vi ((cua triet) OR (cua viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ((ha hoi) or (xa hoi)). hieu ve nam thuc va thanh vi ((cua triet) OR (cua viet))*.