Perhaps you should try some spelling variations:
nang duc » nang luc, nang doc, nang du
ban hanh » ban hang
va trien » va truyen, va thiet, va tuyen
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
hieu va » lieu va, hieu qua
va nang » van nang, da nang, cam nang
duc ban » duc tan, duc van, dua ban
su viet » so viet

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