Perhaps you should try some spelling variations:
ban hang » ngan hang
dua tren » dung tren
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao

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 xa hoi. hieu va cam xuc ((ban hanh) OR (ban hang)) d ((dua tren) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu va cam xuc ((ban hanh) OR (ban hang)) d ((dua tren) OR (cau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu va cam xuc ((ban hanh) OR (ban hang)) d ((dua tren) or (cau tren))*".