Fix citations (#21)

* Replace the incorrect quotation of the Bismuth 82+ wavelength, 'Stringent tests of QED using highly charged ions,' with 'High precision hyperfine measurements in Bismuth challenge bound-state strong-field QED'.

* Added missing DOIs

* Fixed typos and cleaned up URLs

* Fixed 'CMOS Analog Circuit Design' citation

* Replaced conference proceedings with actual paper

Changed `Determination of digital voltmeter input parameters` to `Determination of High-Resolution Digital Voltmeter Input Parameters`

* Fixed incorrect edition of 'Electronic Circuits'

* Added Matplotlib reference

* Added ReactiveX citation

* Added month field to references and cleaned up links

* Bump to 0.18.0

- Fixed a typo
- Updated submodules to latest

Author: PatrickBaus

appendix/list_of_publications.tex

@@ -12,8 +12,7 @@ \chapter*{List of publications}
 
 T. Preuschoff, P. Baus, M. Schlosser and G. Birkl, \textit{Wideband current modulation of diode lasers for frequency stabilization}, Review of Scientific Instruments \textbf{93}, 063002 (2022).\par\vspace{12pt}
 
-Kanika, A. Krishnan, J. W. Klimes, B. Reich, K. Anjum, P. Baus, G. Birkl, W. Quint and M. Vogel, \textit{Production of highly charged ions inside a cryogenic
-Penning trap by electron-impact ionisation}, submitted to Journal of Physics B (2023).\par\vspace{12pt}
+Kanika, A. Krishnan, J. W. Klimes, B. Reich, K. Anjum, P. Baus, G. Birkl, W. Quint and M. Vogel, \textit{Production of highly charged ions inside a cryogenic Penning trap by electron-impact ionisation}, submitted to Journal of Physics B (2023).\par\vspace{12pt}
 
 J. W. Klimes, Kanika, A. Krishnan, B. Reich, K. K. Anjum, P. Baus, G. Birkl, W. Quint, W. Schott, and M. Vogel, \textit{Cryogenic vacuum valve with sub-second operation times}, submitted to Review of Scientific Instruments.\par\vspace{12pt}