Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tinh vai » tinh va, tinh hai, tinh bai
ban tinh » ban thanh, quan tinh, ban hanh
tu sach » su sach, te sach, tu cach
cac cuc » cac cuoc, cac cua, cac nuoc
cua tre » cua te, cua triet, dua tren
cuc ban » cua ban, cac ban, cuu ban
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
ve cac » va cac, vien cac

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) OR (thu sach)) ky dang xa hoi. hieu ve cac cuc ban tinh vai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky dang xa hoi. hieu ve cac cuc ban tinh vai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky dang xa hoi. hieu ve cac cuc ban tinh vai ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky dang xa hoi. hieu ve cac cuc ban tinh vai ((cua tre) or (cuu tre))*.