Perhaps you should try some spelling variations:
dong van » duong van, dang van, dong von
te sach » toc sach
cao suc » cao su
van cua » vang cua, ban cua, dan cua
cao duc » dao duc, giao duc, tao duoc
sach ty » sach y, sach tu, sach thu
hieu va » lieu va
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty nang xa hoi. ((hieu va) or (hieu qua)) ((cao suc) OR (cao duc)) van dong van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang xa hoi. ((hieu va) OR (hieu qua)) ((cao suc) OR (cao duc)) van dong van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang xa hoi. ((hieu va) or (hieu qua)) ((cao suc) OR (cao duc)) van dong van cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang xa hoi. ((hieu va) or (hieu qua)) ((cao suc) OR (cao duc)) van dong van cua tre*.