1. Mal’cev A. I., “On recursive abelian groups,” Dokl. Akad. Nauk SSSR, 46, No. 5, 1009–1012 (1962).
2. Ershov Yu. L., “Existence of constructivizations,” Dokl. Akad. Nauk SSSR, 204, No. 5, 1041–1044 (1972).
3. Goncharov S. S., Molokov A. V., and Romanovskii N. S., “Nilpotent groups of finite algorithmic dimension,” Sibirsk. Mat. Zh., 30, No. 1, 82–88 (1989).
4. Roman’kov V. A. and Khisamiev N. G., “Constructible matrix groups,” Algebra and Logic, 43, No. 3, 339–345 (2004).
5. Latkin I. V., “Arithmetic hierarchy of torsion-free nilpotent groups,” Algebra and Logic, 35, No. 3, 172–175 (1996).