Hiding secondary sources in reference list

Whenever I cite some work whose ideas are based on some other author than that which I am reading, I am required to make this clear in the text, but I am not allowed to cite works I haven’t read myself.

An example:

Mainwaring and Pérez-Liñán (2013) use the work of Linz (1978) and O’Donnel and Schmitter (1986) to develop a typology about waves of democratisation. I want to discuss this new typology, but have not read either of its influences.

I have been doing this manually like I do in this forum, but Mainwaring and Pérez-Liñán (2013) have more works of Linz from 1978, this is their Linz (1978b). Equally, I might want to use more than one work of Linz from 1978. I might want to use Mainwaring and Pérez-Liñán (2013)'s Linz (1978a), or some other author might have cited it or some other Linz (1978), I might even want to make one myself and cite it directly.

If I continue to write secondary references like this manually in the text, Endnote won’t know that, and if I make a direct reference, it’ll show as Linz (1978) even if I already made references Linz (1978a) and Linz (1978b), and this really should be Linz (1978c), even if only this third reference is listed in the reference list.

What I want is for Endnote to keep track of my secondary referencing, but not put it in the reference list.

Citations are meant to include information to find the original source. If you aren’t going to include that in the bibliography, you don’t really “cite” it, but it is just your informational text, and thus there is no reason to insert it as a “non-cited” citation.  I don’t see anyway to have Endnote track that information.