Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
dau thuc » dan thuc, dai thuc, dam thuc
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu cua
va dau » va dao

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 thu ((nang xa) or (lang xa)) hoi. lieu va dau thuc van hanh ((di cua) OR (de cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang xa) OR (lang xa)) hoi. lieu va dau thuc van hanh ((di cua) OR (de cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu ((nang xa) or (lang xa)) hoi. lieu va dau thuc van hanh ((di cua) OR (de cua)) tre*".