Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
hieu hien » bieu hien, chieu chien, dieu khien
nang mai » nang ma, nang tai, lang mai
danh dai » danh dau, danh di, danh sai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
tuoc va » thuoc va, nuoc va, duoc va
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 mai hoi. ((hieu hien) OR (dieu hien)) bach ((tuoc va) or (duc va)) danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang mai hoi. ((hieu hien) OR (dieu hien)) bach ((tuoc va) OR (duc va)) danh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang mai hoi. ((hieu hien) OR (dieu hien)) bach ((tuoc va) or (duc va)) danh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang mai hoi. ((hieu hien) OR (dieu hien)) bach ((tuoc va) or (duc va)) danh dai cua tre*.