Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
sach dao » lanh dao
dao lang » dao khang, dao quang, dao trang
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
hanh lai » hanh lam, hanh tai, thanh lap
su triet » su viet, su tien, ve triet
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach dao lang xa hoi. hieu van cham thuc day hanh lai ((su triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach dao lang xa hoi. hieu van cham thuc day hanh lai ((su triet) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: su sach dao lang xa hoi. hieu van cham thuc day hanh lai ((su triet) or (cua viet))*.