Observation of two-photon interference with continuous variables by homodyne detectionDaohua Wu, Kota Kawamoto, Xiaomin Guo, Katsuyuki Kasai, Masayoshi Watanabe and Yun ZhangEur. Phys. J. D, 71 10 (2017) 260DOI: https://doi.org/10.1140/epjd/e2017-80379-y