Perhaps you should try some spelling variations:
tru nang » tra nang, truc nano, thi nang
tri nang » thi nang, tra nang, tri bang
hieu van » hieu va, thien van, lieu va
te sach » toc sach
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
cao suc » cao su
cao duc » dao duc, giao duc, tao duoc
va cua » va chua, via cua, ca cua
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: te sach ((tru nang) or (tri nang)) xa hoi. hieu van ((cao duc) OR (cao suc)) va danh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((tru nang) OR (tri nang)) xa hoi. hieu van ((cao duc) OR (cao suc)) va danh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((tru nang) or (tri nang)) xa hoi. hieu van ((cao duc) OR (cao suc)) va danh va cua te".
• Adding a wildcard symbol may retrieve word variants: te sach ((tru nang) or (tri nang)) xa hoi. hieu van ((cao duc) OR (cao suc)) va danh va cua te*.