The following handbooks from the Product Development and Management Association (PDMA) are available online:
Leveraging Constraints for Innovation: New product development essentials from the PDMA"This PDMA Essentials Book, Leveraging Constraints for Innovation, the third in this series, provides a framework of individual, organizational, market, and societal constraints, that guides managers in identifying specific constraints related to their innovation activities and provides them with corresponding tools and practices to help them overcome those constraints".
Journal of Product Innovation Management (JPIM) via Wiley Online Library"The Journal of Product Innovation Management (JPIM) is an interdisciplinary, international journal that seeks to advance our theoretical and managerial knowledge of innovation management and product development. The journal publishes original articles on organizations of all sizes (start-ups, small to medium sized enterprises, large corporations) and from the consumer, business-to-business, and policy domains". (publisher website)