Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
hieu van » hieu va, thien van, lieu va
ban dan » ban hang, ban hanh, ban quan
xuc ban » duc ban, cuc ban, quoc ban
lam xuc » cam xuc, lam duoc
van lam » van nam
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
xang x » nang x
dan vi » doan vi, don vi, dan va
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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 ty) OR (sach tu)) xang x hoi. hieu van lam xuc ban dan vi ((dung tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) xang x hoi. hieu van lam xuc ban dan vi ((dung tren) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach tu)) xang x hoi. hieu van lam xuc ban dan vi ((dung tren) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach tu)) xang x hoi. hieu van lam xuc ban dan vi ((dung tren) or (cua te))*.