@software{mpfr:software,
       key = {MPFR},
      type = {free C library},
      note = {MPFR is a C library for multiple-precision floating-point computations
              with correct rounding. The main goal of MPFR is to provide a library
              for multiple-precision floating-point computation which is both
              efficient and has well-defined semantics. MPFR includes most of the
              elementary functions. It also implements the gamma function, and more
              special functions are planned in the future.},
     links = {\URL[MPFR]{http://www.mpfr.org}}}