Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » thien van, lieu va, hieu ve
thanh di » thanh doi, thanh de, thanh do
va thanh » gia thanh, ban thanh, va tinh
nam thuc » nam thuoc, am thuc, nam thu
thu sach » tu sach, thuat sach, thuoc sach
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
ty nang » ky nang, ty xang, ty hang
di cua » dai cua, doi cua, de cua
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: thu sach ty nang ((x hoi) OR (xa hoi)). ((hieu van) or (hieu va)) nam thuc va thanh di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((x hoi) OR (xa hoi)). ((hieu van) OR (hieu va)) nam thuc va thanh di cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty nang ((x hoi) OR (xa hoi)). ((hieu van) or (hieu va)) nam thuc va thanh di cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((x hoi) OR (xa hoi)). ((hieu van) or (hieu va)) nam thuc va thanh di cua triet*.