Perhaps you should try some spelling variations:
chat thuc » thuat thuc, nhan thuc, chat thai
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
hanh cau » nhanh cau, hang cau, hanh cac
hieu cao » chieu cao, hieu cac, hieu ca
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
su triet » su tien, ve triet
tu sach » thu sach, su sach, te sach
su viet » so viet

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 thi hanh cau hoi. hieu cao chat thuc van hanh dai ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hanh cau hoi. hieu cao chat thuc van hanh dai ((su triet) OR (su viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach thi hanh cau hoi. hieu cao chat thuc van hanh dai ((su triet) or (su viet))*.