Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thanh hai » thanh phan, thanh hoa, thanh san
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
ly nang » ky nang, ly hang, ly vang
van bao » van ban, van dao
bao duc » dao duc, bao luc, cao duc
hai cua » thai cua, dai cua, hoi cua
y nang » ky nang, v nang, may nang
x hoi » o hoi, x ho, 5 hoi

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 ((y nang) OR (ly nang)) ((x hoi) or (xa hoi)). hieu van bao duc tan thanh hai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ly nang)) ((x hoi) OR (xa hoi)). hieu van bao duc tan thanh hai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ly nang)) ((x hoi) or (xa hoi)). hieu van bao duc tan thanh hai cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ly nang)) ((x hoi) or (xa hoi)). hieu van bao duc tan thanh hai cua triet*.