@inproceedings{10.1007/BFb0072525,
    Address = {Berlin, Heidelberg},
    Author = {Yeh, Yeong-Nan},
    BookTitle = {Combinatoire {\'e}num{\'e}rative},
    Editor = {Labelle, Gilbert and Leroux, Pierre},
    File = {The calculus of virtual species and K-species - the-calculus-of-virtual-species-and-kspecies - a.pdf},
    ISBN = {978-3-540-47402-9},
    Pages = {351--369},
    Publisher = {Springer Berlin Heidelberg},
    Title = {The calculus of virtual species and K-species},
    Year = {1986},
    date-added = {2023-02-20 12:04:39 +0100},
    date-modified = {2023-02-20 12:04:39 +0100},
    doi = {10.1007/BFb0072525}
}

@inproceedings{10.1007/BFb0072525, Address = {Berlin, Heidelberg}, Author = {Yeh, Yeong-Nan}, BookTitle = {Combinatoire {\'e}num{\'e}rative}, Editor = {Labelle, Gilbert and Leroux, Pierre}, File = {The calculus of virtual species and K-species - the-calculus-of-virtual-species-and-kspecies - a.pdf}, ISBN = {978-3-540-47402-9}, Pages = {351--369}, Publisher = {Springer Berlin Heidelberg}, Title = {The calculus of virtual species and K-species}, Year = {1986}, date-added = {2023-02-20 12:04:39 +0100}, date-modified = {2023-02-20 12:04:39 +0100}, doi = {10.1007/BFb0072525} }