books.google.com - This work attempts to convey a broad understanding of the physical principles underlying the workings of these quantum-based atomic clocks, with introductory chapters placing them in context with the early development of mechanical clocks and the introduction of electronic time-keeping as embodied in...https://books.google.com/books/about/The_Quantum_Beat.html?hl=pl&id=tmdr6Wx_2PYC&utm_source=gb-gplus-shareThe Quantum Beat