Perhaps you should try some spelling variations:
dang hanh » dang thanh, ban hanh, dang van
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
dang xay » dang van, van xay
nam thuc » nam thuoc, am thuc, nam thu
nha hoc » nha thuoc, khoa hoc, nha nuoc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, lang van
hieu ha » hieu hoa, hieu va, hieu ca
vai va » mai va, dai va, hai va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((lang xa) OR (dang xay)) hoi. hieu ha ((nam thuc) or (nha hoc)) dang hanh vai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((lang xa) OR (dang xay)) hoi. hieu ha ((nam thuc) OR (nha hoc)) dang hanh vai va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((lang xa) OR (dang xay)) hoi. hieu ha ((nam thuc) or (nha hoc)) dang hanh vai va triet*".