Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
thanh di » thanh doi, thanh de, thanh do
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
dau luc » cau luc, dau luan, dau nuoc
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
di cua » dai cua, doi cua, de cua
luc va » duc va, tuc va, loc va
y nang » ky nang, ly nang, v nang
cua tu » cua tuc, cua su, cua cu

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