@book{jeffreys:1956:mmp,
    author = {Jeffreys, Harold and Jeffreys, Bertha Swirles},
     title = {Methods of Mathematical Physics},
   edition = {3rd},
      note = {Reprinted in 1999.},
 publisher = {Cambridge University Press},
   address = {Cambridge},
      year = {1956},
   mrclass = {27.0X},
  mrnumber = {MR0074466 (17,590c)},
     zblno = {0070.40402}}