Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va xanh » va danh, va hanh, va anh
xanh di » danh di, vanh dai, xanh tai
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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) OR (thu sach)) ky nang x ho. hieu va cac duc va xanh di ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang x ho. hieu va cac duc va xanh di ((cua tre) OR (cua te))~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang x ho. hieu va cac duc va xanh di ((cua tre) OR (cua te))*.