Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
lang xa » lang ha, dang xay, lang van
sach ty » sach y, sach tu, sach thu
minh va » tinh va, sinh va, sinh vat
chu tre » cho tre, chu tri, cau tren
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ty) or (sach thue)) lang xa hoi. hieu van nam thuc van minh va ((chu tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sach thue)) lang xa hoi. hieu van nam thuc van minh va ((chu tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ty) or (sach thue)) lang xa hoi. hieu van nam thuc van minh va ((chu tre) OR (cuu tre))*".