Synthesis, growth and characterization of a new nonlinear optical material: 4-phenylpyridinium hydrogen squarate (4PHS)
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy (2008) - Comments
pubmed: 17652013  doi: 10.1016/j.saa.2007.06.014  issn: 1386-1425 

C. Ramachandra Raja, P. Paramasivam, N. Vijayan