Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va triet » va thiet, va trien, ve triet
ban hanh » ban hang
phan duc » pham duc, phan tu, phan dau
sach ty » sach y, sach tu, sach thu
duc ban » duc tan, duc van, dua ban
va phan » van phan, va phat, va phap
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
su tien » su kien, su hien, tu tieng

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