D. V. Trung, H. Bui Van, T. T. B. Nguyen, D. B. Pham, T. K. O. Vu, X. T. Nguyen, V. T. Phung, H. M. Pham and G. C. Nguyen, Development of Multi-axis Differential Optical Absorption Spectroscopy System and its Application in Measuring Atmospheric NO\(_2\) Volume Mixing Ratio in Hanoi, Comm. Phys. 32 (2022) 361. DOI: https://doi.org/10.15625/0868-3166/17173.