Our local hobby shop [[and these are rapidly going out of business) had a large sale of older merchandise.

I found the two volume set of the DUR/DSR history of Detroit city lines on sale half off getting both volumes for a total of $25.

These are the CERA bulletins 117 and 120. 117 covers the years of private ownership [[1863-1922) and 120 covers the city owned operations from 1922 to 1956 and also covers transit developments up to 1978 when the book was printed.

I am just starting to read them, but the initial leaf-through had some interesting stuff about some of the rationale for abandonment and busification.