Ya. S. Greenberg and A. A. Shtygashev, Excitation of the collective states of qubits in a three-qubit system, Low Temp. Phys. 46, (2020) [Fiz. Nizk. Temp. 46, 1078-1087, (2020)] DOI: https://doi.org/10.1063/10.0001713.