Book sales in Spain have fallen progressively, which requires urgent changes to optimize the sales process as much as possible. This research proposes a new system, called Base of Reasoning in Artificial Intelligence with Natural Language (BRAIN L) focused exclusively on the publishing industry. The new field of knowledge of Artificial Intelligence (AI), Natural Language Processing (NLP), tecnolog\'ia del Machine Learning is combined with Case-Based Reasoning (CBR) techniques for book recommendations. A model is developed to retrieve similar cases/books supported by NLP techniques for decision making. In addition, policies are implemented to keep the model evaluated by expert reviews, where the system not only learns with new cases, but these cases are real.