Perhaps you should try some spelling variations:
dinh cuu » dinh chi
van hang » van khang, van hoang, van thang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hang » va nang, va lang, va hanh
nam luc » nang luc, nhan luc, nam thuc
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
va nam » van nam, ha nam, va nay
di cuu » di cau, di cua

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 dang xa hoi. hieu va nam luc ((va hang) or (van hang)) ((di cuu) OR (dinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. hieu va nam luc ((va hang) OR (van hang)) ((di cuu) OR (dinh cuu)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang xa hoi. hieu va nam luc ((va hang) or (van hang)) ((di cuu) OR (dinh cuu)) tre*".