D. A. Hill, J. B. Ketterson, R. C. Miller, A. Moretti, R. C. Niemann, L. R. Windmiller, A. Yokosawa, C. F. Hwang,
Dynamic proton polarization in butanol water below 1 K Physical Review Letters. ,vol. 23, pp. 460- 462 ,(1969) ,
10.1103/PHYSREVLETT.23.460