Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
nam thuc » nam thuoc, am thuc, nam thu
va thanh » gia thanh, va tinh, le thanh
dau treo » cau treo, dau theo, dau tien
dau tren » dau tien, dat tren, dau tieng
qua nam » quan nam, cua nam, quang nam
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky nang o hoi. hieu qua nam thuc ((va thanh) OR (ban thanh)) va ((dau treo) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky nang o hoi. hieu qua nam thuc ((va thanh) OR (ban thanh)) va ((dau treo) OR (dau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky nang o hoi. hieu qua nam thuc ((va thanh) OR (ban thanh)) va ((dau treo) or (dau tren))".
• Adding a wildcard symbol may retrieve word variants: tu san ky nang o hoi. hieu qua nam thuc ((va thanh) OR (ban thanh)) va ((dau treo) or (dau tren))*.