Perhaps you should try some spelling variations:
hieu hien » bieu hien, chieu chien, dieu khien
bach tuoc » sach duoc, sach nuoc
dieu hien » dieu khien, dieu kien, bieu hien
cua tre » cua te, cuu tre, cua triet
danh du » danh dau, danh tu, dinh du
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
va danh » va dinh, va dan, va hanh
tuoc va » thuoc va, nuoc va, duoc va
du cua » duy cua, dau cua, dum cua
sac ky » cac ky, sai ky

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

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