Perhaps you should try some spelling variations:
ban thai » ban than, ban thi, ban tai
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cac vuc » cac nuoc, cac vung, cac cuoc
vuc van » duc van, luc van, thuc van
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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. lieu va cac vuc van ban thai ((dua tren) OR (cua te))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. lieu va cac vuc van ban thai ((dua tren) OR (cua te))*.