Perhaps you should try some spelling variations:
khien hach » thien hach, khien thich, khien hoc
hien hanh » dieu hanh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((nang xa) OR (lang xa)) hoi. dieu ((khien hach) or (hien hanh)) nuoc va hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang xa) OR (lang xa)) hoi. dieu ((khien hach) OR (hien hanh)) nuoc va hanh vi cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang xa) OR (lang xa)) hoi. dieu ((khien hach) or (hien hanh)) nuoc va hanh vi cua tu*".