Please help. What program to open pdb format.

E46

Downloaded E-book, whish is pdb format. What program I should usr to open it. TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。4 k6 e, G( _% P4 k; ]4 f
Thank you