Access documents regarding materials, subdivided into purchases, sales and other mentions for each of the various types of materials, as available in the menu in the left navigation bar.

The items in this category may be closely related to those indexed in the objects and transportation categories. Indeed, the "other mentions" category which includes all mentions of materials other than purchases and sales, directs the user to objects when the material of which an article is composed is stated (thus: glass, window), and to transportation when this aspect is expressly mentioned.