Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hac thuc » hoc thuc, thach thuc, thuc thuc
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
ha thuc » va thuc, ha thuy, ha thu
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
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 ky ((nang xa) or (dang xay)) hoi. hieu van ((hac thuc) OR (ha thuc)) va hanh va cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (dang xay)) hoi. hieu van ((hac thuc) OR (ha thuc)) va hanh va cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (dang xay)) hoi. hieu van ((hac thuc) OR (ha thuc)) va hanh va cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (dang xay)) hoi. hieu van ((hac thuc) OR (ha thuc)) va hanh va cua triet*.