Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
va hanh » van hanh, va thanh, va danh
cach su » cach tu, hoach su
hach su » hoach su, hanh su, hoach sau
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu
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 ty)) nang x hoi. hieu thien ((hach su) OR (cach su)) va hanh vi cua tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach ty)) nang x hoi. hieu thien ((hach su) OR (cach su)) va hanh vi cua tu~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang x hoi. hieu thien ((hach su) OR (cach su)) va hanh vi cua tu*.