Perhaps you should try some spelling variations:
van dinh » van minh, van dich, va dinh
dinh thi » dinh tri
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
thi cua » thai cua, thi cuc, tri cua
te sach » toc sach
nang ho » nang hoc, nang co, tang ho
hieu ve » hieu va
suc van » su van, duc van, luc van
cao suc » cao su, cao duc
cua te » cua tu
ho hai » hoc hai, pho hai, cho hai
y nang » ky nang, ly nang, v nang

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) OR (te sach)) y nang ho hai. ((hieu ve) or (hieu van)) cao suc van dinh thi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang ho hai. ((hieu ve) OR (hieu van)) cao suc van dinh thi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) y nang ho hai. ((hieu ve) or (hieu van)) cao suc van dinh thi cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) y nang ho hai. ((hieu ve) or (hieu van)) cao suc van dinh thi cua te*.