Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu cac » hieu luc, hieu va, hieu van
hien cac » thien cac, vien cac, dien cac
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
bao va » bao ve, tao va, ban va
va cua » va chua, via cua, ca 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) or (vu bach)) ky nang xa hoi. hieu ((hien cac) OR (hieu cac)) bao va danh va cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu bach)) ky nang xa hoi. hieu ((hien cac) OR (hieu cac)) bao va danh va cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (vu bach)) ky nang xa hoi. hieu ((hien cac) OR (hieu cac)) bao va danh va cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu bach)) ky nang xa hoi. hieu ((hien cac) OR (hieu cac)) bao va danh va cua triet*.