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
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
luu tre » luu tru, cuu tre, luy tre
ve nam » he nam, va nam, le nam
ve luu » ke luu, vi luu
x hoi » xa hoi, o hoi, x ho

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

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