This document provides an overview of Elsevier's work using machine learning techniques like collaborative filtering and learning to rank to improve article recommendations for researchers. It discusses using collaborative filtering on browsing logs to initially recommend related articles, then using learning to rank to re-rank those recommendations higher based on features like reputation, topics, citations and user engagement data. Evaluation shows the learning to rank approach improved user engagement by 9-10% over collaborative filtering alone. Future work may explore alternative approaches like graph-based methods or deep learning.