Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
ban hanh » ban hang
cuu tre » cua tre, cau treo
tuc ban » thuc ban, truc ban, tu ban
tu sach » thu sach, su sach, te sach
tang xa » trang xa, tang ma, lang xa
sach 6 » sach y, sach 2
ve cai » va cai, ve tai, ve cau
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach 6 tang xa hoi. hieu ((ve cai) OR (ve cac)) tuc ban hanh vi ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach 6 tang xa hoi. hieu ((ve cai) or (ve cac)) tuc ban hanh vi ((cuu tre) OR (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: tu sach 6 tang xa hoi. hieu ((ve cai) or (ve cac)) tuc ban hanh vi ((cuu tre) OR (cau tren))*.