Perhaps you should try some spelling variations:
cham truc » cau truc, nham thuc, pham thuc
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
dau han » dai han, dau ha, dau hai
ly hang » ly quang
ve cham » va cham, ve chat, vu cham

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 ly hang ((dau han) OR (mau han)). hieu ve cham truc van hanh di ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly hang ((dau han) OR (mau han)). hieu ve cham truc van hanh di ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly hang ((dau han) OR (mau han)). hieu ve cham truc van hanh di ((cua triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: su sach ly hang ((dau han) OR (mau han)). hieu ve cham truc van hanh di ((cua triet) or (su triet))*.