diff --git a/index.ipynb b/index.ipynb
index 090b99f..f8f7919 100644
--- a/index.ipynb
+++ b/index.ipynb
@@ -76,10 +76,8 @@
     "\n",
     "* [Rectangular Pulse](fs/FourierSeries_D1483A84E2.ipynb) (D1483A84E2)\n",
     "* [Fourier Series Calculus, Signal and Property Examples](fs/Fourierseries_FB93908026.ipynb) (FB93908026)\n",
-    "* [Fourier Series Calculus, Signal and Property Examples](fs/fourier_series_standalone.ipynb) (obsolete?)\n",
     "\n",
     "### Fourier Transform (FT)\n",
-    "* [Sinc/Rect Duality for FT / DFT / DTFT / FS](ft/fourier_transforms_sinc_rect_duality.ipynb)\n",
     "* [Left-Shifted Rectangular Pulse](ft/FourierTransformation_1CFE5FE3A1.ipynb) (1CFE5FE3A1)\n",
     "* [Right-Shifted Rectangular Pulse](ft/FourierTransformation_A8A2DEE53A.ipynb) (A8A2DEE53A)\n",
     "* [Sinc vs. Rect, Width](ft/FourierTransformation_8C3958BE4F.ipynb) (8C3958BE4F)\n",