diff --git a/source/f90/calltree.txt b/source/f90/calltree.txt
index a24848031c5563e2ef4b3fcb48aa38efa9a622af..90bb8c9a1202ff0870323c124970e16bcbdb2649 100644
--- a/source/f90/calltree.txt
+++ b/source/f90/calltree.txt
@@ -22,4 +22,6 @@ BOSON
       sintr
     sintr
     rcffi
-    respon
\ No newline at end of file
+    respon
+    o1
+    o2
diff --git a/source/f90/doboson.f90 b/source/f90/doboson.f90
index 8ae4b5fa34787af94a441c977672b0ee94a273f0..f2ee66dbea17e971e6e046abdfd697c49005891d 100644
--- a/source/f90/doboson.f90
+++ b/source/f90/doboson.f90
@@ -57,11 +57,6 @@ subroutine doboson(t, width, gauss, asym, emin, emax, wmin, wmax, np, p, xout, y
 ! respon called when the input parameter gauss is < 0 or > 1.
 ! with 0 <= gauss <= 1, r1 and r2 are not used.
 
-! *** rational approximations for ei(u) * exp(-u) + e1(u) * exp(+u)
-! *** in the intervals (0, 1.3) and (1.3, infinity) <accuracy : 4.e-04>
-! *** used for fourier transforming half-lorentzian functions
-
-
   debug = .false.
   data fm1 / 0.0d0 /, fp1 / 0.0d0 /
   pi = 4 * datan(1.0d0)
diff --git a/source/f90/eels.f90 b/source/f90/eels.f90
index d6ac13fb51f7ecf0ce0d3df0cd6e42aca81b6304..ae4558041afc0ae827f85c8b8b02667b42dd56bf 100644
--- a/source/f90/eels.f90
+++ b/source/f90/eels.f90
@@ -30,11 +30,11 @@ program eels
 
   call change_working_dir()
   open(unit = 11, file = 'eelsin')
-! impact energy (ev)
+! impact energy (eV)
   read(11, *) e0
-! incidence angle (%)
+! incidence angle (°)
   read(11, *) theta
-! angular apertures of the elliptic detector (%)
+! angular apertures of the elliptic detector (°)
   read(11, *) phia
   read(11, *) phib
 ! energy-loss interval and step size (cm**-1)
diff --git a/source/f90/o1.f90 b/source/f90/o1.f90
index a346fc08228a5560b82fd67280d118bf702b0d92..16c9bf04a05f45027c587d7847e544f00e09c88d 100644
--- a/source/f90/o1.f90
+++ b/source/f90/o1.f90
@@ -1,5 +1,9 @@
 double precision function o1(u)
 
+! *** rational approximations for ei(u) * exp(-u) + e1(u) * exp(+u)
+! *** in the intervals (0, 1.3) and (1.3, infinity) <accuracy : 4.e-04>
+! *** used for fourier transforming half-lorentzian functions
+
   implicit none
 
   double precision, intent(in) :: u
diff --git a/source/f90/o2.f90 b/source/f90/o2.f90
index 1d4fc3b9670e2e3ca42c2c348313db31b4c5e387..76c562b2d807f2e00fe70f38ca4045f44023bd2b 100644
--- a/source/f90/o2.f90
+++ b/source/f90/o2.f90
@@ -1,5 +1,9 @@
 double precision function o2(u)
 
+! *** rational approximations for ei(u) * exp(-u) + e1(u) * exp(+u)
+! *** in the intervals (0, 1.3) and (1.3, infinity) <accuracy : 4.e-04>
+! *** used for fourier transforming half-lorentzian functions
+
   implicit none
 
   double precision, intent(in) :: u