Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
tham thuc » nham thuc, pham thuc, tam thuc
thanh le » thinh le, thanh ve, thanh de
sach thu » sach thue, sach thieu, sach tham
thuc day » thuc dan, thuc vat
ca viet » va viet, co viet, hoa viet
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
sach ty » sach y, sach tu, xach tay
xang ha » lang ha, tang ha, dang ha
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (sach thu)) xang ha hoi. hieu ve tham thuc day thanh le ((ca viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach thu)) xang ha hoi. hieu ve tham thuc day thanh le ((ca viet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach thu)) xang ha hoi. hieu ve tham thuc day thanh le ((ca viet) or (cua vat))*.