Perhaps you should try some spelling variations:
dua tren » dung tren
ban hang » ngan hang
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
va cam » va cham, va cac, va cao
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 sach ky nang o hoi. hieu va cam xuc ((ban hanh) OR (ban hang)) de ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hoi. hieu va cam xuc ((ban hanh) OR (ban hang)) de ((dua tren) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu va cam xuc ((ban hanh) OR (ban hang)) de ((dua tren) or (cuu tre))*".