Perhaps you should try some spelling variations:
hien bach » vien bach, thien hach, hien hanh
hieu hien » bieu hien, dieu hien, chieu chien
sach ky » sac ky, sach ty, sach kem
va hanh » van hanh, va thanh, va danh
hue va » thue va, nhue va, he va
cua tu » cua tuc, cua cu, cua te
cua su » qua su
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang x hoi. hieu hien bach hue va hanh vi ((cua tu) OR (cua su))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach y)) nang x hoi. hieu hien bach hue va hanh vi ((cua tu) or (cua su))~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach y)) nang x hoi. hieu hien bach hue va hanh vi ((cua tu) or (cua su))*.