Update broken links

HengchengZhang · HengchengZhang · commit 98179904f190 · 2023-05-10T10:00:52.000+10:00
diff --git a/lectures/mle.md b/lectures/mle.md
@@ -636,7 +636,7 @@ print(stats_poisson.summary())
 ```
 
 Now let's replicate results from Daniel Treisman's paper, [Russia's
-Billionaires](https://pubs.aeaweb.org/doi/pdfplus/10.1257/aer.p20161068),
+Billionaires](https://www.aeaweb.org/articles?id=10.1257/aer.p20161068),
 mentioned earlier in the lecture.
 
 Treisman starts by estimating equation {eq}`poissonreg`, where:
diff --git a/lectures/var_dmd.md b/lectures/var_dmd.md
@@ -835,4 +835,4 @@ Counterparts of all of the salient formulas above then apply.
 
 You can find a Python implementation of DMD here:
 
-https://mathlab.github.io/PyDMD/
+https://mathlab.sissa.it/pydmd

Original file line number	Diff line number	Diff line change
`@@ -835,4 +835,4 @@ Counterparts of all of the salient formulas above then apply.`
`835`	`835`
`836`	`836`	`You can find a Python implementation of DMD here:`
`837`	`837`
`838`		`-https://mathlab.github.io/PyDMD/`
	`838`	`+https://mathlab.sissa.it/pydmd`