@article{paciorek:1970:eie,
    author = {Paciorek, K. A.},
     title = {Algorithm 385: {E}xponential integral $\ExpInti(x)$},
   journal = {Comm. ACM},
    number = {7},
    volume = {13},
      year = {1970},
     pages = {446–447},
      note = {Includes Fortran code, maximum accuracy 20D. For
              certification and remarks see same journal v. 13 (1970),
              pp. 448–449 and p. 750; v. 15 (1972), p. 1074.},
      issn = {0001-0782},
       doi = {10.1145/362686.362696}}