Perhaps you should try some spelling variations:
cua triet » su triet, va triet
doanh van » doan van, doanh va, doanh ban
va doanh » van doanh, vay doanh, va danh
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » co hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va am » va lam, va cam

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 nang ((cao hoi) OR (cau hoi)). hieu va am thuc va doanh van ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((cao hoi) OR (cau hoi)). hieu va am thuc va doanh van ((cua triet) OR (cua viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((cao hoi) OR (cau hoi)). hieu va am thuc va doanh van ((cua triet) or (cua viet))*".