Aaron Harris' Advanced Studies for Trumpet and Cornet
This is a fantastic etude book with studies in all major and minor keys.
Each study contains scales, a technical etude with various articulation models, then a contrasting etude that is more melodic in nature. The book covers each Major Key and the Relative Minor Key associated with it. Mastering every key should be essential to any musician and this is one of the tools to do that.
An improved version of this trumpet book should be in everyone’s library.