Source : Free On-Line Dictionary of Computing

SYGMA
     
        A symbolic generator and macro assembler by A.P. Ershov et al
        of Novosibirsk.  For the {BESM-6}, {M-220} and {Minsk-22}.
     
        ["SYGMA, A Symbolic Generator and Macroassembler", A.P. Ershov
        et al, in Symbol Manipulation Languages and Techniques,
        D.G. Bobrow ed, N-H 1968, pp.226- 246].