Perhaps you should try some spelling variations:
hien bach » vien bach, thien hach, hien hanh
hieu hien » bieu hien, dieu hien, chieu chien
danh doi » danh di, thanh doi, dung doi
doi cua » dai cua, hoi cua
duoc va » nuoc va, duc va, duoc ma
tuoc va » thuoc va, nuoc va, tuc va
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
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: so sach ty ((nang xa) OR (nang ma)) hoi. hieu hien bach ((tuoc va) or (duoc va)) danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (nang ma)) hoi. hieu hien bach ((tuoc va) OR (duoc va)) danh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) OR (nang ma)) hoi. hieu hien bach ((tuoc va) or (duoc va)) danh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) OR (nang ma)) hoi. hieu hien bach ((tuoc va) or (duoc va)) danh doi cua tre*.