Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua viet » ca viet, hoa viet, cua dieu
hanh vai » hanh vi, hanh va, hanh tai
sach thi » sach thu, sach tai, sach thieu
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu vi » hieu voi, hieu va, hieu ve
vi tham » vi pham, va tham, vi than
hang ca » hang va, nang cao, hang tai
hang xa » hoang xa, hang va, lang xa

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 ((hang xa) or (hang ca)) hoi. hieu vi tham thuc va hanh vai ((cua viet) OR (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi ((hang xa) OR (hang ca)) hoi. hieu vi tham thuc va hanh vai ((cua viet) OR (cua vat)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi ((hang xa) or (hang ca)) hoi. hieu vi tham thuc va hanh vai ((cua viet) OR (cua vat))".
• Adding a wildcard symbol may retrieve word variants: tu sach thi ((hang xa) or (hang ca)) hoi. hieu vi tham thuc va hanh vai ((cua viet) OR (cua vat))*.