I'm trying to start at the beginning of this story, the problem is just that.. there is more than one.
French webcartoonist Marion Montaigne maintains a blog called Tu Mourras Moins Bête. I don't speak French, so I don't even know what that means. He makes satiric webcomics which depict funny facts and stories from science and history. The comics featured on his blog are so successful, they got released to YouTube as animated short films, three minutes each.
The short films are available in German too, and that's the reason I know about them.

There is one episode about weird science experiments, based on this blog entry: http://tumourrasmoinsbete.blogspot.com/2011/03/lundi-cest-debilogie.html

It mentions a study by M. W. Schein and E.B. Hale called "Stimuli Eliciting Sexual Behavior" where they have watched the sexual behavior of male turkeys when confronted with a model of a female turkey. They found out that if they take away the female body, i.e. only putting a female's head in front of the male turkey, it still shows a sexual response and tries to copulate with the fake head.
Here is a story about it: https://www.atlasobscura.com/articles/how-to-seduce-a-turkey-the-bizarre-poultry-sex-experiments-of-the-1960s

I find this very fascinating. It's in a similar spirit to that one radio story by SWR2 where they explored self-experiments throughout history. Great stuff! (It's called "Am eigenen Leib - Selbstversuche in Naturwissenschaft und Medizin" in case the link is dead)

Naturally, I wanted to find the original paper on the turkey study, but it's not available online. Luckily, I found a library that has the book where the study was published.
I borrowed the book and made a digital copy of the study, using only software freely available on the internet. Here is how to do it:

  1. Scan the pages - my first try was using a smartphone camera, but the images were distorted. It's possible to correct this using some apps on Android or PC, but the result are not that great. I ended up scanning the pages to a USB stick using a big office machine at a public school nearby.
  2. Optimize the images for optimum legibility. I was using ScanTailor Advanced which is surprisingly good. It can cut/split the image files and correct several flaws of scanned documents automatically.
  3. Combine the pages to a PDF file. I tried a freemium program called PDF24 first, but it is far too "user-friendly" to be of any use. I just wanted to merge some files in an automated way, so I ended up using ImageMagick.
    My final command line (I wanted to re-order some pages): magick convert img-227151636-00{23..28}* img-227153036-0001_1L.tif img-227151636-00{01..22}* -adjoin merged2.pdf
    Note that I've used a bash shell here. Not sure what the equivalent in Windows PowerShell would be.

So, now I finally got what I wanted and learned some new skills along the way. I'm pretty happy with the results.