So as I am studying the crus of Barolo and Barbaresco, I am finding a good amount of vineyard names that are found within the different crus listed on bottles, but very little resources to which crus exactly. For example, Ratti's "Marcenasco" Barolo is located in La Morra, but it is not listed as a cru. I know it is located near the town of Annunziata, but I want to know which cru it is a sub zone of, there are several options (Annunziata, Conca, Giachini or Rocche dell'Annunziata). And is their a source to find our all or at least the important sub zones?
Marcenasco is a blended Barolo, but the original source (1965 to 1969) was from the Conca vineyard. The name comes from San Martino di Marcenasco, the former name of Annunziata.
Note that each of the individual villages submitted crus for MGA and some (Monforte d'Alba and Barolo) registered all while others (Serralunga d'Alba, Castiglione Falletto) only registered historical crus, which can sometimes explain why there's such a wide variation as to what's been registered.
The best source for Barolo MGAs is the book by Masnaghetti (Barolo MGA) who also did all of the Enogea maps. From what I understand, it's currently out of print but he's releasing a volume 2 shortly, however the pack of maps that he has for the iPad covering the villages of Barolo is amazing. For Barbaresco it's a little more difficult but I've relied on the simple Enogea map.
Masnaghetti also made a Barbaresco MGA book. Rare Wine Co has that for sale and is also accepting preorders for Volume 2 of the Barolo MGA book. They are expensive, but worth it.