Perhaps you should try some spelling variations:
thanh de » hanh de, thanh ve, thanh do
sach thu » sach thue, sach thieu, sach tham
thuc dan » thuc hanh, hoc dan, thuc vat
thuc va » thuc vat, thuc day
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
sach ty » sach y, sach tu, xach tay
xang ha » lang ha, tang ha, dang ha
ha hoi » hoa hoi, ha noi, xa hoi
de cua » le cua, te cua, dieu cua

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 cham ((thuc va) OR (thuc dan)) thanh de 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 cham ((thuc va) OR (thuc dan)) thanh de cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sach thu)) xang ha hoi. hieu ve cham ((thuc va) OR (thuc dan)) thanh de cua vat".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach thu)) xang ha hoi. hieu ve cham ((thuc va) OR (thuc dan)) thanh de cua vat*.