“…EPR at Work, a special thematic issue of Concepts in Magnetic Resonance, written by James Hyde and us, brings into an easily accessible volume, with updates, many of the informally published documents that stimulated the early development of EPR [235]. Many of the volumes in the Biological Magnetic Resonance series provide chapters that extend and enhance the content of the present article: in vivo [61], distance measurements [236], instrumentation and calculational methods [237,238], high-frequency [239], biomedical [60,66], membranes [59], metalloproteins [240] EPR.…”