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Hene spektrum. Spektrum einer HeliumNeonRhre hinter einem optischen Gitter selfphotographed Stefan Diskussion PDrelease Original upload log de Wdwdbot CommonsHelper de Henespektrum StefanPohl bytes no Information Spektrum einer HeliumNeonRhre hinter einem optischen Gitter selbst fotografiert Genehmigung Heliumneon lasers