Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hien hanh » dieu hanh
su sach » so sach, vu sach
hoi cua » hoi chuc
doi cua » dai cua
duoc va » nuoc va, duc va, duoc ma
sach ky » sac ky, sach y, sach ty
tuoc va » thuoc va, nuoc va, tuc va
nang xa » nang x, lang xa, nang ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang xa hoi. hieu hien hanh ((tuoc va) or (duoc va)) danh ((doi cua) OR (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu hien hanh ((tuoc va) OR (duoc va)) danh ((doi cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. hieu hien hanh ((tuoc va) or (duoc va)) danh ((doi cua) OR (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu hien hanh ((tuoc va) or (duoc va)) danh ((doi cua) OR (hoi cua)) tre*.