Alan Heeger, Physics, phase transitions e.g. ‘Mechanism for first-order magnetic transition in Fehr system’ J. Appl. Phys. 40 3 1368 (1969)
The Laboratory for Research on the Structure of Matter 
Alan Heeger, Physics, phase transitions e.g. ‘Mechanism for first-order magnetic transition in Fehr system’ J. Appl. Phys. 40 3 1368 (1969)