diff --git a/docs/awesome_table_in_html.Rmd b/docs/awesome_table_in_html.Rmd
index 473ecf0..3af994c 100644
--- a/docs/awesome_table_in_html.Rmd
+++ b/docs/awesome_table_in_html.Rmd
@@ -452,4 +452,4 @@
 Since the structure of `kable` is relatively simple, it shouldn't be too difficult to convert HTML or LaTeX tables generated by other packages to a `kable` object and then use `kableExtra` to modify the outputs. If you are a package author, feel free to reach out to me and we can collaborate. 
 
 ## `tables`
-The latest version of [`tables`](https://cran.r-project.org/web/packages/tables/index.html) comes with a `toKable()` function, which is compatiable with functions in `kableExtra` (>=0.9.0).
+The latest version of [`tables`](https://CRAN.R-project.org/package=tables) comes with a `toKable()` function, which is compatiable with functions in `kableExtra` (>=0.9.0).
diff --git a/docs/awesome_table_in_html.html b/docs/awesome_table_in_html.html
index ea829e1..a2b79c7 100644
--- a/docs/awesome_table_in_html.html
+++ b/docs/awesome_table_in_html.html
@@ -3556,7 +3556,7 @@
 2
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -3572,7 +3572,7 @@
 4
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3588,7 +3588,7 @@
 6
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -3596,7 +3596,7 @@
 7
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3607,7 +3607,7 @@
 8
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3615,7 +3615,7 @@
 9
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -3623,7 +3623,7 @@
 10
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3645,7 +3645,7 @@
 12
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -3664,7 +3664,7 @@
 14
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -8952,7 +8952,7 @@
 <p>Since the structure of <code>kable</code> is relatively simple, it shouldn’t be too difficult to convert HTML or LaTeX tables generated by other packages to a <code>kable</code> object and then use <code>kableExtra</code> to modify the outputs. If you are a package author, feel free to reach out to me and we can collaborate.</p>
 <div id="tables" class="section level2">
 <h2><code>tables</code></h2>
-<p>The latest version of <a href="https://cran.r-project.org/web/packages/tables/index.html"><code>tables</code></a> comes with a <code>toKable()</code> function, which is compatiable with functions in <code>kableExtra</code> (&gt;=0.9.0).</p>
+<p>The latest version of <a href="https://CRAN.R-project.org/package=tables"><code>tables</code></a> comes with a <code>toKable()</code> function, which is compatiable with functions in <code>kableExtra</code> (&gt;=0.9.0).</p>
 </div>
 </div>
 
diff --git a/docs/awesome_table_in_pdf.Rmd b/docs/awesome_table_in_pdf.Rmd
index a5965db..5be9621 100644
--- a/docs/awesome_table_in_pdf.Rmd
+++ b/docs/awesome_table_in_pdf.Rmd
@@ -359,7 +359,7 @@
 ## Group rows via multi-row cell
 Function `group_rows` is great for showing simple structural information on rows but sometimes people may need to show structural information with multiple layers. When it happens, you may consider using `collapse_rows` instead, which will put repeating cells in columns into multi-row cells.  
 
-In LaTeX, `collapse_rows` adds some extra hlines to help differentiate groups. You can customize this behavior using the `latex_hline` argument. You can choose from `full` (default), `major` and `none`. Vertical alignment of cells is controlled by the `valign` option. You can choose from "top"(default), "middle" and "bottom".
+In LaTeX, `collapse_rows` adds some extra hlines to help differentiate groups. You can customize this behavior using the `latex_hline` argument. You can choose from `full` (default), `major` and `none`. Vertical alignment of cells is controlled by the `valign` option. You can choose from "top", "middle"(default) and "bottom". Be cautious that the vertical alignment option was only introduced in multirow in 2016. If you are using a legacy LaTeX distribution, you will run into trouble if you set `valign` to be either "top" or "bottom".
 
 ```{r}
 collapse_rows_dt <- data.frame(C1 = c(rep("a", 10), rep("b", 5)),
@@ -368,7 +368,7 @@
                  C4 = sample(c(0,1), 15, replace = TRUE))
 kable(collapse_rows_dt, "latex", booktabs = T, align = "c") %>%
   column_spec(1, bold=T) %>%
-  collapse_rows(columns = 1:2, latex_hline = "major", valign = "top")
+  collapse_rows(columns = 1:2, latex_hline = "major", valign = "middle")
 ```
 
 Right now, you can't automatically make striped rows based on collapsed rows but you can do it manually via the `extra_latex_after` option in `row_spec`. This feature is not officially supported. I'm only document it here if you want to give it a try. 
@@ -524,4 +524,4 @@
 Since the structure of `kable` is relatively simple, it shouldn't be too difficult to convert HTML or LaTeX tables generated by other packages to a `kable` object and then use `kableExtra` to modify the outputs. If you are a package author, feel free to reach out to me and we can collaborate. 
 
 ## `tables`
-The latest version of [`tables`](https://cran.r-project.org/web/packages/tables/index.html) comes with a `toKable()` function, which is compatiable with functions in `kableExtra` (>=0.9.0).
+The latest version of [`tables`](https://CRAN.R-project.org/package=tables) comes with a `toKable()` function, which is compatiable with functions in `kableExtra` (>=0.9.0).
diff --git a/docs/awesome_table_in_pdf.pdf b/docs/awesome_table_in_pdf.pdf
index 4ba5441..90d7b15 100644
--- a/docs/awesome_table_in_pdf.pdf
+++ b/docs/awesome_table_in_pdf.pdf
Binary files differ