Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hieu van » hieu va, thien van, lieu va
thanh le » thinh le, thanh ve, thanh de
va thanh » gia thanh, ban thanh, va tinh
van tham » van thanh, van tuan, van chat
ca viet » va viet, co viet, hoa viet
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach thu, xach tay
xang ha » lang ha, tang ha, dang ha
sach tu » sach thu, cach tu, sach uu
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 tu)) xang ha hoi. hieu van tham thuc va 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 tu)) xang ha hoi. hieu van tham thuc va thanh le ((ca viet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach tu)) xang ha hoi. hieu van tham thuc va thanh le ((ca viet) or (cua vat))*.