• England, Lancashire, Cheshire, Yorkshire, Parish Registers, 1603-1910

• England, Lancashire, Cheshire, Yorkshire, Parish Registers, 1603-1910, Lancashire

• Digital Archives Association Ordnance Survey 25 inch first edition  1888 – 1893 Maps of Lancashire
• Digital Archives Association Ordnance Survey 6 inch first edition 1841 - 1853 Maps of Lancashire
   

Some downloadable books at the Internet Archive that are relevant to Bolton or Lancashire

•  Lancashire, its history, legends, and manufactures. [Assisted by residents in various parts of the county]
  
•  The place names of Lancashire, their origin and history
•  The Song of Solomon in the Lancashire dialect, as spoken at Bolton. From the authorized English version
•  A glossary of the Lancashire dialect