Hello Streamline, and welcome to the Aerodrome
I am glad that you find the information here useful, but I am not quite sure what the problem is with citing references.
If I want to cite something that has been posted here, then I normally cite it as "The Aerodrome" or something similar, and give the name or handle of the author, and the date posted. If I am citing it from a post of my own I usually provide a hyperlink as well.
To search the forum for information on SPAD XIII you can use the "Search" function at the top of this page (you need to be registered and logged on) and just type in <SPAD XIII> (without <>) to retrieve all posts.
For information that is cited here, but not posted or quoted in full, it is good practice, I think, to quote the printed source or provide a hyperlink to the electronic copy so that the reference can be followed in the 'usual' way - in my case, the 'usual way' means requesting the printed book or article from my local library's 'interlibrary loan' service. This is a valuable service provided by all the UK Public and Academic libraries (the former at a small nominal charge), and I guess the same is true for US and most European libraries as well. I am often amazed by how many 'forumites' here say that something is impossible to get hold of, when I often know that it is available for loan in this way via the library service. With my own Public Library (Hampshire) even books from libraries in other countries can be obtained for loan in this way, although in this case the charge is much greater as the borrower has to pay the return postage. Many of the out of print books cited are also available, at a cost, from seconhand booksellers such as Amazon and AbeBooks
Bletchley