In local and regional studies glacial extension mapping is a way to compare which of them was larger and the largest one. In Alpine regions this method has been used since the beginning of the XX century (for example Penck & Brückner 1906), but that method is based on actualism principles of the present landscape and neglect how was the ancient topography of a mountain range. In that sense is better to compare the different snow Equilibrium Line Altitude (ELA) for each glaciation because is not only related with the maximum extent for each glaciation, and also had some climatic connotations that permits you to compare regardless other mountain ranges, but in essence it depends on latitude (in the equator there is no mountain range too high enough in the world; close to equator 6000 m a.s.l like the glaciers in Kilimanjaro; at 40ºN 3000 m a.s.l like in the Pyrenees; at 80ºN 0 m a.s.l like in Svalbard). For large ice sheets that problem is not so important and only the maximum extent for each glaciation is enough to compare which was bigger or the biggest one, nevertheless is well known that the isotopic Oxygen stratigraphy and glaciations are very close related, so looking at marine sediments or ice cores you can evaluate the temperature evolution for each glacial/interglacial period and at the end compare between those periods. You have plenty of climatic "proxys" that can guide you in that sense, but if you can develop your question then maybe I can help you better.

Your querry is so general that it is hard to answer. If I were to start looking, I would go to recent books on glacial geology (glacial geomorphology). The standard texts on pure glaciology are more focused on the details of glacial behavior than on past fluctuations in glacial extent and thickness. That said, if you are focused on a specific region or time, there is a good chance that you could find something in the Journal of Glaciology. There are some general rules however. The more recent the event, the more we know about it in that new events tend to obscure older events. Also a factor is the accessability of the region of interest. For instance we know a lot about past glacial activity in the Alps and in the central part of the US. Good luck hunting.

Thank you, my question was too limited. Jack