Theology of the past, for the present
So, you want to dig deeper into theological retrieval? Here are some resources to help you do that.
First, start with Theological Retrieval for Evangelicals by Gavin Ortlund. Ortlund is a historical theologian and in this book he both makes the case for the necessity of theological retrieval and shows how it ought to be done.
Ortlund also has a YouTube channel, Truth Unites, in which he engages in theological retrieval (among other things).
After checking out that book, here are some more resources for theological retrieval that I have found helpful:
Christian Classics Ethereal Library
Post-Reformation Digital Library
Greystone Theological Institute
The Center for Baptist Renewal
Reformed Retrieval 