Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dang xay » dang van, van xay
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
pham duy » pham duc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duy van » duy vat, dung van
nang ma » tang ma, sang ma, nang cao
lai cua » dai cua, hai cua, lai chau
tu sach » thu sach, su sach, te sach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang ma) or (dang xay)) hoi. hieu ve pham duy van hanh lai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang ma) OR (dang xay)) hoi. hieu ve pham duy van hanh lai cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang ma) or (dang xay)) hoi. hieu ve pham duy van hanh lai cua triet*.