How did IKEA develop the characteristic style? I know there is a catalog each year, but I'm looking more for a summary and overview of the design evolution. I understand it's not as significant as, for example, Braun's design for which a design history article exists. Nonetheless IKEA is a term many are familiar with and the furniture is found in many urban homes (at least in Europe).
Check Harvard Business Review. I've bought their "IKEA and Ingvar Kamprad" and "IKEA Invades America" articles (each are about $5) which both include information regarding some of their earlier approaches to design.