Morris, M.S. (1989) Initial Condition for Perturbations in R +εR2 Cosmology. Physical Review D, 39, 1511-1516.
http://authors.library.caltech.edu/6670/1/MORprd89.pdf.
https://doi.org/10.1103/PhysRevD.39.1511

has been cited by the following article:

• TITLE: Initial Conditions for Defining an Arrow of Time at the Start of Inflation?

  AUTHORS: Andrew Walcott Beckwith

  KEYWORDS: Times Arrow, Degrees of Freedom

  JOURNAL NAME: Journal of High Energy Physics, Gravitation and Cosmology, Vol.4 No.4, October 31, 2018

  ABSTRACT: This investigation sets forth initial conditions for a start of the arrow of time in cosmology based upon the idea that of having initial degrees of freedom set as g*~ 1000 initially, instead of a maximum value of g*~ 100-120 for the number of degrees of freedom during the electro weak era.