If you are interested in original material, I have had success with http://www.archive.org
which is a huge searchable collection of archived library material. I ended up in the biodiversity library and found this...http://www.biodiversitylibrary.org/bibl ... 3#/summary
--a 100 year old (1912-1914) monthly magazine called The Aquarium. The articles are fascinating and the advertising is a real kick. I thought it was really interesting to see what has and hasn't changed in the practice of keeping an aquarium in a century of time.
If you are willing to spend a bit of time with the search function, you can drag up some amazing and fun stuff.