Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh chai » tranh chap, tranh cai, tranh thai
tien chat » tieng nhat, tinh chat, tien cua
chai khoa » thai khoa, chi khoa, pham khoa
thu sach » thuat sach, thuoc sach, thu hoach
chat hoa » thuat hoa, chat va, chat huu
tu sach » su sach, tu cach, vu sach
te sach » toc sach

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)) tien chat hoa hoc ) OR ( te sach tranh chai khoa hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((tu sach) OR (thu sach)) tien chat hoa hoc ) or ( te sach tranh chai khoa hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( ((tu sach) OR (thu sach)) tien chat hoa hoc ) or ( te sach tranh chai khoa hoc ))*.