Editing Bell test (section)

=== Tittel et al. (1998) ===
The Geneva 1998 Bell test experiments showed that distance did not destroy the "entanglement". Light was sent in fibre optic cables over distances of several kilometers before it was analysed. As with almost all Bell tests since about 1985, a "parametric down-conversion" (PDC) source was used.<ref name="Title-1998a">{{cite journal |author1=W. Tittel |author2=J. Brendel |author3=B. Gisin |author4=T. Herzog |author5=H. Zbinden |author6-link=N. Gisin |author6=N. Gisin |year=1998 |title=Experimental demonstration of quantum-correlations over more than 10 kilometers |journal=Physical Review A |volume=57 |issue=5 |pages=3229–3232 |arxiv=quant-ph/9707042 |doi=10.1103/PhysRevA.57.3229|bibcode = 1998PhRvA..57.3229T|s2cid=55253956 }}</ref><ref name="Title-1998b">{{cite journal |author1=W. Tittel |author2=J. Brendel |author3=H. Zbinden |author4=N. Gisin |year=1998 |title=Violation of Bell inequalities by photons more than 10 km apart |journal=Physical Review Letters |volume=81 |issue=17 |pages=3563–6 |arxiv=quant-ph/9806043 |doi=10.1103/PhysRevLett.81.3563|bibcode = 1998PhRvL..81.3563T|s2cid=55712217 }}</ref>