@article{10_4064_sm150_2_7,
     author = {Xiaohui Gu and Miao Li and Falun Huang},
     title = {Almost periodicity of $C$-semigroups,
integrated semigroups and $C$-cosine functions},
     journal = {Studia Mathematica},
     pages = {189--200},
     year = {2002},
     volume = {150},
     number = {2},
     doi = {10.4064/sm150-2-7},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm150-2-7/}
}