Perhaps you should try some spelling variations:
hang diem » hang dien, lang diem, hoang dieu
cau tren » cu tren, dau tren, ca tren
diem cau » dieu can
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
va hang » van hang, va nang, va lang
thuc va » thuc vat, thuc dan, thuc day
ky lang » ky nang, ky dang, ky tang
so sanh » do sanh
lang xa » lang ha, dang xay, lang van

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) OR (toc sach))) or (so sanh)) ky lang xa hoi. hieu van nam thuc va hang diem cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((te sach) OR (toc sach))) OR (so sanh)) ky lang xa hoi. hieu van nam thuc va hang diem cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((te sach) OR (toc sach))) or (so sanh)) ky lang xa hoi. hieu van nam thuc va hang diem cau tren".
• Adding a wildcard symbol may retrieve word variants: ((((te sach) OR (toc sach))) or (so sanh)) ky lang xa hoi. hieu van nam thuc va hang diem cau tren*.