Perhaps you should try some spelling variations:
hien bach » vien bach, thien hach, hien hanh
hieu hien » bieu hien, dieu hien, chieu chien
danh dum » danh du, anh duc, danh tu
thuoc va » thuc va, thuoc ma, thuong va
dum cua » duy cua, dam cua, dung cua
duoc va » nuoc va, duc va, duoc ma
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet

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) or (nang ma)) hoi. hieu hien bach ((thuoc va) or (duoc va)) danh dum cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu hien bach ((thuoc va) OR (duoc va)) danh dum cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (nang ma)) hoi. hieu hien bach ((thuoc va) or (duoc va)) danh dum cua tre*.