Perhaps you should try some spelling variations:
tru nang » tra nang, tri nang, truc nano
hieu van » hieu va, thien van, lieu va
sach tru » sach truc, sach thu, sach tu
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
cao duc » dao duc, giao duc, tao duoc
cao suc » cao su
hanh va » hang va, hanh vi
danh va » doanh va, anh va, dan va
cua te » cua tu

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