Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va trien » va truyen, va thiet, va tuyen
ban hanh » ban hang
nhan luc » nang luc
su triet » su viet, su tien, ve triet
tay lang » tai lang, tay tang, tay quang
hieu va » lieu va, hieu qua
luc ban » duc ban, cuc ban, luc bat
ty lang » ty xang, ty hang, tu lang
va nhan » van nhan, ca nhan, va phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty lang) OR (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty lang) OR (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty lang) OR (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty lang) OR (tay lang)) xa hoi. hieu va nhan luc ban hanh vi ((va trien) or (su triet))*.