Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu hien » bieu hien, dieu hien, chieu chien
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, dua tren
su sach » so sach, vu sach
cac lo » cac lop, cac co, cac bo
lo va » lo van, lao va, ly 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. hieu hien cac lo va dinh vai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu hien cac lo va dinh vai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (nang ma)) hoi. hieu hien cac lo va dinh vai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (nang ma)) hoi. hieu hien cac lo va dinh vai ((cua tre) or (cua triet))*.