https://modelingthesp.blogspot.com/2011/03/choosing-model-car-fleet-7-hoppers.html?m=0
modeling the SP: Choosing a model car fleet, Part 7: hoppers
Modeling the SP in California means that hopper cars are simply not very visible, and moreover company cars will almost all be ballast cars ...
choosing a modelcar fleetmodelingsp
https://www.ideals.illinois.edu/items/17875
Choosing a model of sentence picture comparisons : a reply to Catlin and Jones | IDEALS
choosing a model