Perhaps you should try some spelling variations:
qua nhan » cua nhan, qua nhat, qua phan
nhan cac » nhan cach, phan cac, nhan mac
ban hanh » ban hang
va triet » va thiet, va trien, ve triet
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
cac ban » cac dan, cac van, can ban
su hien » su kien, su tien, thu hien
sac ky » cac ky, sai ky

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 ky) or (sac ky)) nang xa hoi. hieu qua nhan cac ban hanh vi ((va triet) or (su hien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang xa hoi. hieu qua nhan cac ban hanh vi ((va triet) OR (su hien)).
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sac ky)) nang xa hoi. hieu qua nhan cac ban hanh vi ((va triet) or (su hien))*.