First author(s): the individual(s) who organized and conducted the study. Typically there is only a single first author, but nowadays there are often two first authors. This is because the amount of research required to generate “high impact” publications simply can’t be done by a single person. Typically, the first author is a Ph.D. student or lab scientist.

Middle authors: Individuals that provide critical effort, help, feedback, or guidance for the study and publication of the research. Different fields/labs have varying stringencies for what is considered “middle authorship worthy”. In many labs, simply being present and helping with the research warrants authorship. In other labs, you need to contribute a lot of energy to the project to be included as an author.

Senior author(s): The primary investigators (PI’s) or lead researchers that run the lab that conducted and published the study. The senior authors are typically the ones that acquire funding and oversee all aspects of the published research. PI’s have varying degrees of hands-on management.

There is some variation in whether the central research question for a manuscript is developed by the first vs. the senior author, but usually it’s the senior author. Also, the first and senior authors typically write the manuscript and seek edits/feedback from middle authors. In other cases, there can be dedicated writers that write the manuscript, who sometimes do/don’t get middle authorship. A main takeaway is: the general outline I’ve provided above is not strictly adhered to.

I’ll take some liberty to apply this outline to this article at hand:

First Author: G. Newton (OP). The scientist who mostly likely conducted all of the data mining and analysis. He likely wrote the article as well.

Middle Author: A. Callahan. It seems like this author was a grad student at the time the article was written. She likely performed essential work for the paper’s publication. This could’ve been: helping with the analysis, data mining, or ideation.

Senior Author: M. Dumontier. A data science professor, now at Maastricht U. He’s a highly cited scientist!

Lastly… if you check out the acknowledgements, you can see three additional names. These people likely helped with setting up compute access, editing, or general ideation.

This is a cool manuscript! Hopefully this overview isn’t TMI and provides some insight into the biomedical/data science publication process.

I can't speak for the OP, but you can buy optical media of old out-of-print magazines scanned as PDFs.

I bought the entirety of Desert Magazine from 1937-1985. It arrived on something like 15 CD-ROMS.

I drag-and-dropped the entire collection into iBooks, and read them when I'm on the train.

(Yes, they're probably on archive.org for free, but this is far easier and more convenient, and I prefer to support publishers rather than undermine their efforts.)

There is a significant issue with copyright, though. I'll remove anything with a valid DMCA, but 99.9% of the world's historical magazine issues are now in IP limbo as their ownership is probably unknown. Most of the other .1% aren't overly concerned as distribution is their goal and their main income is advertising, not sales.