Our books are balanced between theory and practice. Because of this, they enjoy widespread popularity. Our vision was to create a international series of books that focussed on signal processing and filtering. These books would document the technology of the times and evolve as the technology evolved. We began with active filters, then moved to digital filters, and adaptive filters. Our philosophy was devote about half of the book to theory that was technology independent, and the other half of the book to technology dependent designs. This insures their long-term value.
Our books are widely acclaimed and referenced. We believe this is due primarily to the balance between theory and practice. They continue to provide references for industrial audiences and resources for academic teaching.