Bookmark 8.2 Business & EconomicsNon-fiction David J. Bland and Alexander Osterwalder – Testing Business Ideas: Book Review & Audio Summary by Stephen Dale November 11, 2025 by Stephen Dale November 11, 2025 Discover how Testing Business Ideas by David J. Bland and Alexander Osterwalder teaches entrepreneurs to validate business concepts through experimentation and data. 0 FacebookTwitterPinterestEmail