@article{Nakamura:2023Dy, author = "Nakamura, Kouji", title = "{Proposal of a gauge-invariant treatment of l=0,1-mode perturbations on the Schwarzschild background spacetime}", doi = "10.22323/1.444.1543", journal = "PoS", year = 2023, volume = "ICRC2023", pages = "1543" }