Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
su triet » su viet, su tien, ve triet
dinh vai » dinh van, dinh vi, dinh va
hien cac » thien cac, vien cac, hieu cac
nang ma » tang ma, sang ma, nang cao
sach ky » sac ky, sach y, sach ty
va dinh » van dinh, va kinh, va tinh
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
cac co » cac cong
co va » co ma, do va, so va

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. dieu hien cac co va dinh vai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. dieu hien cac co va dinh vai ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (nang ma)) hoi. dieu hien cac co va dinh vai ((cua tre) or (su triet))*.