Robuta

https://www.nist.gov/publications/nonlinear-and-quantum-atom-optics
atom opticsnonlinearquantumnist
https://www.arxiv.org/abs/0904.0150
Abstract page for arXiv paper 0904.0150: Hidden symmetry and nonlinear paraxial atom optics
atom opticshiddensymmetrynonlinearparaxial