diff --git a/docs/d3-shape/curve.md b/docs/d3-shape/curve.md
index 9af8d208e5fd9c..f247fe004f1b96 100644
--- a/docs/d3-shape/curve.md
+++ b/docs/d3-shape/curve.md
@@ -59,7 +59,7 @@ If desired, you can implement a [custom curve](#custom-curves). For an example o
 
 <ExampleCurve label="beta" :curves='ticks.map((t) => ({curve: "bundle", tension: t}))' />
 
-[Source](https://github.com/d3/d3-shape/blob/main/src/curve/bundle.js) · Produces a straightened cubic [basis spline](https://en.wikipedia.org/wiki/B-spline) using the specified control points, with the spline straightened according to the curve’s [*beta*](#curveBundle_beta), which defaults to 0.85. This curve is typically used in [hierarchical edge bundling](https://observablehq.com/@d3/hierarchical-edge-bundling) to disambiguate connections, as proposed by [Danny Holten](https://www.win.tue.nl/vis1/home/dholten/) in [Hierarchical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data](https://www.win.tue.nl/vis1/home/dholten/papers/bundles_infovis.pdf). This curve does not implement [*curve*.areaStart](#curve_areaStart) and [*curve*.areaEnd](#curve_areaEnd); it is intended to work with [d3.line](./line.md), not [d3.area](./area.md).
+[Source](https://github.com/d3/d3-shape/blob/main/src/curve/bundle.js) · Produces a straightened cubic [basis spline](https://en.wikipedia.org/wiki/B-spline) using the specified control points, with the spline straightened according to the curve’s [*beta*](#curveBundle_beta), which defaults to 0.85. This curve is typically used in [hierarchical edge bundling](https://observablehq.com/@d3/hierarchical-edge-bundling) to disambiguate connections, as proposed by [Danny Holten](https://web.archive.org/web/20170606120738/https://www.win.tue.nl/vis1/home/dholten/) in [Hierarchical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data](https://web.archive.org/web/20170813165351/https://www.win.tue.nl/vis1/home/dholten/papers/bundles_infovis.pdf). This curve does not implement [*curve*.areaStart](#curve_areaStart) and [*curve*.areaEnd](#curve_areaEnd); it is intended to work with [d3.line](./line.md), not [d3.area](./area.md).
 
 ## curveBundle.beta(*beta*) {#curveBundle_beta}