Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
su triet » su viet, su tien, ve triet
hanh lai » hanh lam, hanh tai, thanh lap
cam thuc » am thuc, nam thuc, cam thu
sach tai » sach bai, sach tham, sach dao
hieu van » hieu va, thien van, lieu va
lang van » dang van, tang van, hoang van
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
lang xa » lang ha, dang xay
su sach » so sach, vu sach

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 tai ((lang xa) or (lang van)) hoi. hieu van cam thuc va hanh lai ((su triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tai ((lang xa) OR (lang van)) hoi. hieu van cam thuc va hanh lai ((su triet) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: su sach tai ((lang xa) or (lang van)) hoi. hieu van cam thuc va hanh lai ((su triet) or (cua viet))*.