The following list of Chapter 23 links has been included for convenience.

 

• Details of the Beauty Camera Company Zoom Biokor Lens can be found at  
  https://web.archive.org/web/20210730180226/https://www.asahi-net.or.jp/~hw6k-asi/old-lens/old-lens-biokor50-100.html
  or 
  https://www.asahi-net.or.jp/~hw6k-asi/old-lens/old-lens-biokor50-100.html
  which is the live address but some images were missing when I visited.​