Geometric spin echo under zero field | Nature Communications
Excited-state spin coherence of a single nitrogen–vacancy centre in diamond | Nature Physics
File:Spin Echo Diagram.png - Wikimedia Commons
Hahn echo nutation NMR references
MRI sequences: Spin echo
Neutron spin echo monitoring of segmental-like diffusion of water confined in the cores of carbon nanotubes - Physical Chemistry Chemical Physics (RSC Publishing)