Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
bao duc » dao duc, bao luc, cao duc
san cua » sang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
y nang » ly nang, v nang, may nang
x hoi » xa hoi, o hoi, x ho

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