> round(results, 3)
      [,1] 
[1,] 0.071  (delta1, standard sandwich)
[2,] 0.034  (delta2, Ts^2 compared to F with 1 and dhat degrees of freedom)
[3,] 0.055  (delta3, Ts^2 compared to F with 1 and dtilde degrees of freedom)
[4,] 0.031  (delta4, Ta^2 compared to F with 1 and dhatH degrees of freedom)
[5,] 0.050  (delta5, Ta^2 compared to F with 1 and dtildeH degrees of freedom)
[6,] 0.059  (Mancl and DeRouen bias corrected compared to chi^2 with 1 df)
[7,] 0.045  (Mancl and DeRouen bias corrected compared to F with 1 and K-1=19df)
[8,] 0.044  (Mancl and DeRouen bias corrected compared to F with 1 and K-2=18df)