Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh tai, hanh van
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
hoa hoi » khoa hoi, hoa doi, hoc hoi
ky lang » ky nang, ky dang, ky tang
ve am » va am

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 ky lang ((hoa hoi) OR (hoa hoc)). hieu ve am thuc va ((hanh vai) or (hanh va)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((hoa hoi) OR (hoa hoc)). hieu ve am thuc va ((hanh vai) OR (hanh va)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((hoa hoi) OR (hoa hoc)). hieu ve am thuc va ((hanh vai) or (hanh va)) cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ((hoa hoi) OR (hoa hoc)). hieu ve am thuc va ((hanh vai) or (hanh va)) cua triet*.