Articles and adjectives

In 5.8 I found it difficult to remember the Case, Adjective ending and Articles associated with one another. I then realised that the 3 separate groupings could easily be combined and made my learning easier. Thought I'd share it. It's now just a single group.
                                   Definite article     Indefinite article           No article
M     Nom                der alte Mann         ein alter Mann                  alter Mann
M     Acc                   den alten Mann      einen alten Mann            alten Mann
F     Nom  +  Acc    die alte Frau            eine alte Frau                    alte Frau
N     Nom  + Acc    das alte Pferd          ein altes Pferd                  altes Pferd
P     Nom  + Acc    die alten Freunde   meine alten Freunde     alte Freunde

Meine is not an indefinite article; there is no plural form.  I know what you intended, but it always helps to correctly label grammar.

I agree that meine is not an indefinite article, but I find the nomenclature a bit confusing.
One grammar book I have divides it into possessive adjectives and possessive pronouns, and the other into possessive determiners and possessive pronouns.
The possessive adjective/ determiner meine declines like the indefinite article except that is does have a plural form like keine.
The possessive pronoun declines like dieser.

Maybe Peter could have used keine in the example. ( a bit sad though :) )