Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
thien hach » thien thanh, hien hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hach su » hoach su, cach su, hanh su
va hanh » van hanh, va thanh, va danh
cua tu » cua tuc, cua cu, cua te
cua su » qua su
x hoi » o hoi, x ho, 5 hoi
su va » su van, tu va

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 nang ((x hoi) OR (xa hoi)). hieu thien hach su va hanh vi ((cua tu) OR (cua su))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (xa hoi)). hieu thien hach su va hanh vi ((cua tu) OR (cua su))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (xa hoi)). hieu thien hach su va hanh vi ((cua tu) OR (cua su))*.