Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
va xanh » va danh, va hanh, va anh
cac duc » cac du, cao duc, cac dac
qua cac » cua cac
nang o » nang co, nang ho, nang ro
di cuu » di cau, dinh cuu
di cua » dai cua, doi cua, de cua
o hoi » co hoi, o hoc, o hai

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