Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, cao hoc, tao hoi
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
tinh vu » tinh va, tinh tu, tinh su
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi
vu va » vu van, tu va, su va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((cao hoi) OR (co hoi)). ((hieu ve) OR (lieu va)) cau thuc va tinh vu va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((cao hoi) OR (co hoi)). ((hieu ve) or (lieu va)) cau thuc va tinh vu va triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((cao hoi) OR (co hoi)). ((hieu ve) or (lieu va)) cau thuc va tinh vu va triet*.