[n] W. Sch?Âllkopf et al., “The FHI FEL Upgrade Design”, in Proc. FEL'19, Hamburg, Germany, Aug. 2019, pp. 52-55. doi:10.18429/JACoW-FEL2019-TUP006
%\cite{Sch?Âllkopf:FEL19-TUP006} \bibitem{Sch?Âllkopf:FEL19-TUP006} W. Sch?Âllkopf \emph{et al.}, \textquotedblleft{The FHI FEL Upgrade Design}\textquotedblright, in \emph{Proc. FEL’19}, Hamburg, Germany, Aug. 2019, pp. 52--55. \url{doi:10.18429/JACoW-FEL2019-TUP006}
@inproceedings{sch?âllkopf:fel19-tup006, author = {W. Sch?Âllkopf and others}, title = {{The FHI FEL Upgrade Design}}, booktitle = {Proc. FEL'19}, pages = {52--55}, paper = {TUP006}, venue = {Hamburg, Germany, Aug. 2019}, publisher = {JACoW Publishing, Geneva, Switzerland}, doi = {10.18429/JACoW-FEL2019-TUP006}, url = {https://jacow.org/fel2019/papers/TUP006.pdf}, language = {english} }