B.  Kolbinger, Amsler, C., S. Cuendis, A., Breuker, H., Capon, A., Costantini, G., Dupre, P., Fleck, M., Gligorova, A., Higaki, H., Kanai, Y., Kletzl, V., Kuroda, N., Lanz, A., Leali, M., Mäckel, V., Malbrunot, C., Mascagna, V., Massiczek, O., Matsuda, Y., Murtagh, D. J., Nagata, Y., Nanda, A., Nowak, L., Radics, B., Sauerzopf, C., Simon, M. C., Tajima, M., Torii, H. A., Uggerhøj, U., Ulmer, S., Venturelli, L., Weiser, A., Wiesinger, M., Widmann, E., Wolz, T., Yamazaki, Y., and Zmeskal, J., ?Measurement of the principal quantum number distribution in a beam of antihydrogen atoms?, vol. 75, no. 3, p. 91, 2021.

C.  Malbrunot, Amsler, C., S. Cuendis, A., Breuker, H., Dupre, P., Fleck, M., Higaki, H., Kanai, Y., Kolbinger, B., Kuroda, N., Leali, M., Mäckel, V., Mascagna, V., Massiczek, O., Matsuda, Y., Nagata, Y., Simon, M. C., Spitzer, H., Tajima, M., Ulmer, S., Venturelli, L., Widmann, E., Wiesinger, M., Yamazaki, Y., and Zmeskal, J., ?The ASACUSA antihydrogen and hydrogen program: results and prospects?, Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, vol. 376, 2018.

E.  Widmann, Amsler, C., S. Cuendis, A., Breuker, H., Diermaier, M., Dupre, P., Evans, C., Fleck, M., Gligorova, A., Higaki, H., Kanai, Y., Kolbinger, B., Kuroda, N., Leali, M., Leite, A. M. M., Mäckel, V., Malbrunot, C., Mascagna, V., Massiczek, O., Matsuda, Y., Murtagh, D. J., Nagata, Y., Nanda, A., Phan, D., Sauerzopf, C., Simon, M. C., Tajima, M., Spitzer, H., Strube, M., Ulmer, S., Venturelli, L., Wiesinger, M., Yamazaki, Y., and Zmeskal, J., ?Hyperfine spectroscopy of hydrogen and antihydrogen in ASACUSA?, Hyperfine Interactions, vol. 240, p. 5, 2018.