Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh tai » thanh tai, hang tai, han tai
hanh dai » hanh dao, vanh dai, thanh dat
thuc day » thuc dan, thuc vat
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi
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 ty nang ((x hoi) or (o hoi)). hieu ve am thuc day ((hanh dai) OR (hanh tai)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoi)). hieu ve am thuc day ((hanh dai) OR (hanh tai)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((x hoi) or (o hoi)). hieu ve am thuc day ((hanh dai) OR (hanh tai)) cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) or (o hoi)). hieu ve am thuc day ((hanh dai) OR (hanh tai)) cua triet*.