@techreport{NA-07/17,
  title = "Computing $A^{\alpha}$, log(A) and related matrix functions by contour integrals",
  author = "Nicholas Hale and Nicholas J Higham and Lloyd N Trefethen",
  year = "2007",
  institution = "Oxford University Computing Laboratory",
  month = "August",
  number = "NA-07/17",
}