Perhaps you should try some spelling variations:
dang xay » dang van, van xay
cam thuc » am thuc, nam thuc, cam thu
sach hoi » sach moi, cach thoi, hoach hoi
hieu van » hieu va, thien van, lieu va
sach doi » sach moi, sach dao, sach bai
xay hoi » xa hoi, tay hoi, cay phoi
van cam » van nam, van lam, van cau
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai va » mai va, dai va, hai va
vi va » vi van, vu va, bi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach hoi) or (sach doi)) dang xay hoi. hieu van cam thuc va hanh ((vi va) OR (vai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach hoi) OR (sach doi)) dang xay hoi. hieu van cam thuc va hanh ((vi va) OR (vai va)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach hoi) or (sach doi)) dang xay hoi. hieu van cam thuc va hanh ((vi va) OR (vai va)) triet*".