Restrained Least-Squares Refinement of the Crystal Structure of the Ribonuclease T1(Asterisk)2(Prime)-Guanylic Acid Complex at 1.9 Angstroms Resolution
Arni, R., Heinemann, U., Maslowska, M., Tokuoka, R., Saenger, W.(1987) Acta Crystallogr B 43: 548