Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
dum tren » dua tren, duc tren, duoc tren
hieu va » lieu va, hieu qua
sach ly » sach y, sach lo, sach ty
te sach » toc sach
hieu ve » hieu van
ly nang » ky nang, ly hang, ly vang
cac xuc » cam xuc, cac nuoc, chat xuc
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va

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 ly nang x ho. ((hieu ve) or (hieu va)) cac xuc va dan vi ((dum tren) OR (dung tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly nang x ho. ((hieu ve) OR (hieu va)) cac xuc va dan vi ((dum tren) OR (dung tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly nang x ho. ((hieu ve) or (hieu va)) cac xuc va dan vi ((dum tren) OR (dung tren))".
• Adding a wildcard symbol may retrieve word variants: te sach ly nang x ho. ((hieu ve) or (hieu va)) cac xuc va dan vi ((dum tren) OR (dung tren))*.