Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dung sai » dung tai, dung va, dung dat
danh dau » lanh dao, hang dau, danh tu
sach ky » sac ky, sach ty, sach kem
hieu he » hieu ve, hiem he, hieu le
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
he nam » ha nam, nghe nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) OR (sach y)) nang ma hoi. hieu he nam thu ha ((danh dau) or (dung sai)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) nang ma hoi. hieu he nam thu ha ((danh dau) OR (dung sai)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sach y)) nang ma hoi. hieu he nam thu ha ((danh dau) or (dung sai)) cua triet".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sach y)) nang ma hoi. hieu he nam thu ha ((danh dau) or (dung sai)) cua triet*.