Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai
vi su » va su, ve su, ki su

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 (nang x)) hoi. hieu ((ve cam) OR (ve cac)) duc van hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang x)) hoi. hieu ((ve cam) OR (ve cac)) duc van hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (nang x)) hoi. hieu ((ve cam) OR (ve cac)) duc van hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang x)) hoi. hieu ((ve cam) OR (ve cac)) duc van hanh vi su triet*.