Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thanh lam » thanh lap, hanh lam, thanh nam
hieu van » hieu va, thien van, lieu va
lam cua » nam cua, lam chat
chu duc » thu duc, chua duoc, cuu duoc
cau duc » cao duc, cau luc, cau truc
tu sach » thu sach, te sach, tu cach
nang co » nang cao, nang doc, nang noi
su sach » so sach, vu sach
co hoi » co hoc, co loi

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) OR (su sach)) ky nang co hoi. hieu van ((cau duc) or (chu duc)) gia thanh lam cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang co hoi. hieu van ((cau duc) OR (chu duc)) gia thanh lam cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang co hoi. hieu van ((cau duc) or (chu duc)) gia thanh lam cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang co hoi. hieu van ((cau duc) or (chu duc)) gia thanh lam cua triet*.