Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
duc van » duc va, duc tan, duc manh
su viet » so viet
ve cai » va cai, ve cac, ve tai
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: su sach ky lang xa hoi. hieu ((ve cai) or (va cac)) duc van hanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. hieu ((ve cai) OR (va cac)) duc van hanh vi su viet.
• Adding a wildcard symbol may retrieve word variants: su sach ky lang xa hoi. hieu ((ve cai) or (va cac)) duc van hanh vi su viet*.