Perhaps you should try some spelling variations:
hien hanh » dieu hanh
dieu hien » dieu khien, dieu kien, bieu hien
truc may » tren may, truc va
xuc may » xuc hay, phuc may
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
huu tri » huu tai
va huu » vu huu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sach ty)) nang x hoi. dieu hien hanh ((xuc may) OR (truc may)) tich va huu tri~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang x hoi. dieu hien hanh ((xuc may) OR (truc may)) tich va huu tri.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach ty)) nang x hoi. dieu hien hanh ((xuc may) OR (truc may)) tich va huu tri".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach ty)) nang x hoi. dieu hien hanh ((xuc may) OR (truc may)) tich va huu tri*.