All these free-space profiles for sources are listed here: Category:Source (There also is link on that page to a YouTube video that gives some explanation.)
All of them have the same basic format. To create a new source Free-Space profile, copy one of those listed on that page and make a new Free-Space profile for your source. Just delete the old information and put in your new information about the new source (title, author, publisher, links, etc.). That will give you the same structure and features (such as the WhatLinksHere link). You can then add tags, categories, additional information, and links to your own page (such as Space:Data_Entry_of_the_Descendants_of_Aquilla_Greer).
If you have specific questions, send me a private message.