Perhaps you should try some spelling variations:
ve triet » va trien, su triet
hanh dai » hanh tai, hanh dao, vanh dai
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
ca viet » va viet, co viet, hoa viet
o hai » co hai, so hai, o lai
ve am » va am
o hoi » co hoi, o hoc, o hoa

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 ty nang ((o hoi) OR (o hai)). hieu ve am thuc va hanh dai ((ve triet) OR (ca viet))~.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((o hoi) or (o hai)). hieu ve am thuc va hanh dai ((ve triet) or (ca viet))*.