Set editable to False and default to your default value.
And you can expose it under the name 'reference' by making it a property, but it won't show up in any ModelForms, inlcuding the admin.
There are a couple of things I'd like to comment about your code. First of all in save it should say reference and not collection, and the super should be idented inside save. You where forgetting to pass the arguments in super too.
It should look like this.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.