Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cam thuc » am thuc, nam thuc, cam thu
sach thu » sach thue, sach thieu, sach tham
lang van » dang van, tang van, hoang van
thuc ban » thuoc ban, thuc dan, thu ban
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, xach tay
van hoe » van hoa, van hoc, van hieu
ve cam » ve cham, ve cac, va cam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) lang van hoe. hieu ve cam thuc ban thanh ((le cua) OR (ly cua)) vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach thu)) lang van hoe. hieu ve cam thuc ban thanh ((le cua) OR (ly cua)) vat~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) lang van hoe. hieu ve cam thuc ban thanh ((le cua) OR (ly cua)) vat*.