Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
thi van » thi lan, thi hanh, thi nang
ca tren » cau tren, cu tren, la tren
nam tu » nam thu, nam thuc
x hoi » xa hoi, o hoi, x ho
vi ca » vit ca, li ca, va ca

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 ky nang x hoi. ((thien van) or (thi van)) nam tu ((va thanh) OR (ban thanh)) vi ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((thien van) OR (thi van)) nam tu ((va thanh) OR (ban thanh)) vi ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((thien van) or (thi van)) nam tu ((va thanh) OR (ban thanh)) vi ca tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((thien van) or (thi van)) nam tu ((va thanh) OR (ban thanh)) vi ca tren*.