Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
dan hang » ban hang, van hang, dat hang
thuc dan » thuc hanh, hoc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
cay phoi » cap phoi, tay hoi, cay cho
xay hoi » xa hoi, tay hoi, gay thoi
ky dang » ky nang, ky danh
hieu ve » hieu va, hieu van
so sanh » do sanh
hang vi » hang va, hanh vi, hang di
te sach » toc sach
ve nam » he nam, va nam, le nam
vi cau » va cau, ve cau, di cau

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