Perhaps you should try some spelling variations:
khien cac » hien cac, khien cau, thien cac
dinh vai » dinh van, dinh vi, dinh va
su triet » su viet, su tien, ve triet
va dinh » van dinh, va kinh, va tinh
nang ma » tang ma, nang cao, mang may
cua tre » cua te, cuu tre, cua triet
sang ma » tang ma, sang tao, mang may
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
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 sac ky ((nang ma) or (sang ma)) hoi. dieu khien cac lo va dinh vai ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang ma) OR (sang ma)) hoi. dieu khien cac lo va dinh vai ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: su sac ky ((nang ma) or (sang ma)) hoi. dieu khien cac lo va dinh vai ((cua tre) or (su triet))*.