janiko

This plugin allows references and citations in your posts. It’s only a beta version, so if you find issues or if you think it lacks some features, please contact me.
To use it, simply add your reference using a shortcode you can choose (‘jref’ by default), and a few attributes (always use lowercase):
<ul>
<li>title (mandatory)</li>
<li>author</li>
<li>date</li>
<li>url</li>
<li>editor</li>
<li>page</li>
<li>lang</li>
<li>readon</li>
</ul>
There are no specific controls on the content of those attributes, you may add any text you want. Only ‘title’ is mandatory. All attributes roles are easy to understand; ‘page’ is for a book (but can be used for any content), ‘readon’ is the date you last consult the reference.
Again, in this first release, there’s no specific control or action triggered by attribute’s content (like verifying the format, or linking to an archive site). Maybe in a future release…
A list of all references will be added at the end of the post.
Here are some examples:
<ul>
<li>[jref]url=http://geba.fr|date=janv 2017|title=The Title.|author=Janiko|lang=FR|editor=geba.fr|page=p.5[/jref]</li>
<li>[jref name=’numref’]url=http://geba.fr|date=janv 2017|title=The Title.|author=Janiko|lang=FR|editor=geba.fr|page=p.5[/jref]</li>
<li>[jref name=’numref’ /]</li>
</ul>
You can optionnaly add a name to the citation, so you can reuse it in your post. Important note: the displayed attributes will be the attributes of the FIRST reference with that name. Any other attribute will be ignored.

JReferences

This plugin adds references and citations functionalities (in a wikipedia-like style).

Dan Griffiths

Widgit

Simple Attribution is just that… simple! It adds a meta box on post pages 
which allows bloggers to specify the name and URL of the site a sourced article 
originated from. Assuming both these fields are filled out, it appends the 
attribution link to the bottom of the post.
Simple Attribution allows links to be generated in both text and image form, 
allowing you to customize it to the feel of your website. Natively, it includes 
5 icons which can be used to identify the attribution link instead of the 
standard caption (which is editable through the options panel), and custom 
icons can be used as well.
Don’t like where we put the link? You have the option to disable 
auto-attribution and put the link wherever you want it to display simply by 
adding <?php echo display_attribution(); ?> to your template!

Simple Attribution

I used it on newly installed wordpress 5.8 with default theme.
The problem is that, it didn't save the attribution title and url and also didn't show the links at bottom of the post.

I wish it work on new version. If it has git page, I can resolve it.

Thanks.

Didn't work on standard wordpress 5.8

A simple plugin to allow bloggers to add attribution to sourced posts.

JReferences vs Simple Attribution