Absorption spectrum in the wings of the potassium second resonance doublet broadened by helium, F. Shindo, J. F. Babb, K. Kirby, and K. Yoshino, J. Phys. B 40, 2841 (2007). Read the preprint abstract (this link also contains links to get the entire preprint.)

Accurate long-range coefficients for two excited like isotope He atoms: He(2 ¹P)-He(2 ¹P), He(2 ¹P)-He(2 ³P), and He(2 ³P)-He(2 ³P), J.-Y. Zhang, Z.-C. Yan, D. Vrinceanu, J. F. Babb, H. R. Sadeghpour, Phys. Rev. A 76, 012723 (2007). Read the preprint abstract (this link also contains links to get the entire preprint.)

Long-range interactions for He(nS)-He(n'S) and He(nS)-He(n'P), J.-Y. Zhang, Z.-C. Yan, D. Vrinceanu, J. F. Babb, H. R. Sadeghpour, Phys. Rev. A 74, 014704 (2006). Read the preprint abstract (this link also contains links to get the entire preprint.)