Perhaps you should try some spelling variations:
thien van » thi van
cua triet » cua viet, su triet, va triet
thu sach » tu sach, thuat sach, thuoc sach
bac nuoc » bach tuoc, sach nuoc, hoc nuoc
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nang tri » nang tai, lang tri, nang thi
va nang » van nang, da nang, cam nang
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang ((x hoi) OR (o hoi)). thien van ((bac nuoc) or (cac nuoc)) va nang tri cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((x hoi) OR (o hoi)). thien van ((bac nuoc) OR (cac nuoc)) va nang tri cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang ((x hoi) OR (o hoi)). thien van ((bac nuoc) or (cac nuoc)) va nang tri cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ((x hoi) OR (o hoi)). thien van ((bac nuoc) or (cac nuoc)) va nang tri cua triet*.