diff --git a/src/Python3/challenger.ipynb b/src/Python3/challenger.ipynb
index 7ad065e1b6c7363aac85c4c86fb37ec0e17dd22d..5562e299875b6e2067ac2fe79be1740fc5cebde9 100644
--- a/src/Python3/challenger.ipynb
+++ b/src/Python3/challenger.ipynb
@@ -577,7 +577,7 @@
    "metadata": {},
    "source": [
     "The maximum likelyhood estimator of the intercept and of Temperature are thus $\\hat{\\alpha}=5.0849$ and $\\hat{\\beta}=-0.1156$. This **corresponds** to the values from the article of Dalal et al. The standard errors are $s_{\\hat{\\alpha}} = 7.477$ and $s_{\\hat{\\beta}} = 0.115$, which is **different** from the $3.052$ and $0.04702$ reported by Dallal et al. The deviance is $3.01444$ with 21 degrees of freedom. I cannot find any value similar to the Goodness of fit ($G^2=18.086$) reported by Dalal et al.\n",
-    "**I have therefore managed to partially replicate the results of the Dalal et. al. article**."
+    "**I have therefore managed to partially replicate the results of the Dalal et al. article**."
    ]
   },
   {
diff --git a/src/R/challenger.Rmd b/src/R/challenger.Rmd
index 751735abb992cd9e7ffa45392e0c9f46c7d5d865..49be3ee61a9ce4f23d5aebcd2746e485a8703fd1 100644
--- a/src/R/challenger.Rmd
+++ b/src/R/challenger.Rmd
@@ -47,7 +47,7 @@ logistic_reg = glm(data=data, Malfunction/Count ~ Temperature, weights=Count,
 summary(logistic_reg)
 ```
 
-The maximum likelyhood estimator of the intercept and of Temperature are thus $\hat{\alpha}=5.0849$ and $\hat{\beta}=-0.1156$ and their standard errors are $s_{\hat{\alpha}} = 3.052$ and $s_{\hat{\beta}} = 0.04702$. The Residual deviance corresponds to the Goodness of fit $G^2=18.086$ with 21 degrees of freedom. **I have therefore managed to replicate the results of the Dalal et. al. article**.
+The maximum likelyhood estimator of the intercept and of Temperature are thus $\hat{\alpha}=5.0849$ and $\hat{\beta}=-0.1156$ and their standard errors are $s_{\hat{\alpha}} = 3.052$ and $s_{\hat{\beta}} = 0.04702$. The Residual deviance corresponds to the Goodness of fit $G^2=18.086$ with 21 degrees of freedom. **I have therefore managed to replicate the results of the Dalal et al. article**.
 
 # Predicting failure probability
 The temperature when launching the shuttle was 31°F. Let's try to