Perhaps you should try some spelling variations:
cam trung » cam truong, nam trung, cac trung
ve triet » va trien, su triet
va triet » va thiet, va trien, cua triet
trung va » truong va, trang va, trung ha
dinh vi » dinh ve, dinh viet, dinh tri
va dinh » van dinh, va kinh, va tinh
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
ve cam » ve cham, ve cac, va cam

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 y ((nang xa) or (nang ma)) hoi. hieu ve cam trung va dinh vi ((va triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang ma)) hoi. hieu ve cam trung va dinh vi ((va triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang xa) or (nang ma)) hoi. hieu ve cam trung va dinh vi ((va triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) or (nang ma)) hoi. hieu ve cam trung va dinh vi ((va triet) OR (ve triet))*.