Cite method in dffs_m.f90 as
----------------------------
Analytical formula for numerical evaluations of the Wigner rotation matrices at high spins
Naoki Tajima
Phys. Rev. C 91, 014320 – Published 22 January 2015

@article{PhysRevC.91.014320,
  title = {Analytical formula for numerical evaluations of the Wigner rotation matrices at high spins},
  author = {Tajima, Naoki},
  journal = {Phys. Rev. C},
  volume = {91},
  issue = {1},
  pages = {014320},
  numpages = {5},
  year = {2015},
  month = {Jan},
  publisher = {American Physical Society},
  doi = {10.1103/PhysRevC.91.014320},
  url = {http:https://link.aps.org/doi/10.1103/PhysRevC.91.014320}
}

Cite method in wigner_d.f90 as
------------------------------
X. M. Feng, P. Wang, W. Yang, and G. R. Jin,
'High-precision evaluation of Wigner's d matrix by exact diagonalization',
Phys. Rev. E 92, 043307

@article{PhysRevE.92.043307,
  title = {High-precision evaluation of Wigner's $d$ matrix by exact diagonalization},
  author = {Feng, X. M. and Wang, P. and Yang, W. and Jin, G. R.},
  journal = {Phys. Rev. E},
  volume = {92},
  issue = {4},
  pages = {043307},
  numpages = {5},
  year = {2015},
  month = {Oct},
  publisher = {American Physical Society},
  doi = {10.1103/PhysRevE.92.043307},
  url = {https://link.aps.org/doi/10.1103/PhysRevE.92.043307}
}