Precession of Binary Star PSR 1913+16

I am wondering if the following method for calculating the
relativistic precession of a highly eccentric orbit has a name, or is
available in some published document?

Using the system parameters found in http://www.johnstonsarchive.net/relativity/binpulsar.html
:

The orbit radius is taken to be the average of one half of the
separation distances at apastron and periastron:
r = (1576800e3 + 373300e3) / 2.

The average orbit velocity, where M is an average mass of 1.414 solar
masses:
v = sqrt(G*M / r)

The combined orbit circumference is:
C = 2 * (2*pi*r)

The orbit time is:
t = C / v

The precession rate in orbits per orbit, where e is the average orbit
eccentricity (0.617131):
n = 2*pi*(1 - cos(asin(v/c))) / (1 - e*e)

Converted to degrees per Earth year:
d = n * (365/(t/24/60/60)) * 360 = 4.4,

where modern General Relativity provides an approximation of 4.2
degrees per year.

If you are interested, I have put up a short PDF document online,
which includes C++ source code:
http://cavekitty.com/archives/The_Relativistic_Precession_of_Binary_Star_PSR_1913+16.zip

Thank you for any information that you can provide.
- Shawn

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