Perhaps you should try some spelling variations:
ban hanh » ban hang
van viet » san viet, gian viet, tran viet
tu sach » thu sach, su sach, te 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
van dau » van dao, phan dau
tuc ban » thuc ban, truc ban, tu ban

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 lang xa hoi. hieu ((van dau) or (van nam)) tuc ban hanh vi van viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. hieu ((van dau) OR (van nam)) tuc ban hanh vi van viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. hieu ((van dau) or (van nam)) tuc ban hanh vi van viet*.