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Joseph Helffrich
open-in-new
<h2 id="external-links">External links</h2> <ul><li><a href="/facts/2290_Helffrich/RmzSXP0D">Asteroid 2290 Helffrich</a></li> <li><a href="https://web.archive.org/web/20040623072916/http://www.lsw.uni-heidelberg.de/personnel/diss.phtml">List of Dissertations at the Landessternwarte Heidelberg-Königstuhl</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"Minor Planet Discoverers (by number)". Minor Planet Center. 4 September 2016. Retrieved 7 September 2016. <a href="http://www.minorplanetcenter.net/iau/lists/MPDiscsNum.html" target="_blank">http://www.minorplanetcenter.net/iau/lists/MPDiscsNum.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> </ol>