diff --git a/articles/Normal distribution - Wikipedia/Normal distribution - Wikipedia.xopp.xml b/articles/Normal distribution - Wikipedia/Normal distribution - Wikipedia.xopp.xml
index 6ba2297..9ce2343 100644
--- a/articles/Normal distribution - Wikipedia/Normal distribution - Wikipedia.xopp.xml	
+++ b/articles/Normal distribution - Wikipedia/Normal distribution - Wikipedia.xopp.xml	
@@ -66,7 +66,10 @@
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="9"/>
-    <layer/>
+    <layer>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">57.22865585 190.21949453 370.93056821 190.21949453</stroke>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">59.15928360 199.99833540 250.42372678 199.99833540</stroke>
+    </layer>
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="10"/>
@@ -106,7 +109,25 @@
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="19"/>
-    <layer/>
+    <layer>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">43.75012611 186.68397005 179.92884605 186.68397005</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">44.47964755 203.12235178 259.00853688 203.12235178</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">345.83175281 202.17143918 420.43887546 202.17143918</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">42.89462507 212.65142772 377.33950818 212.65142772</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">427.70521936 199.40869040 550.54281601 199.40869040</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">389.24167097 218.84374697 555.62601173 218.84374697</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">44.96596155 231.00921379 555.76160279 231.00921379</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">44.29056467 241.06783276 119.64378640 241.06783276</stroke>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">70.86857567 300.02716317 312.14594133 300.02716317</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">70.40367442 258.51574102 147.32264062 258.51574102</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">202.36102648 258.81501505 292.87501528 258.81501505</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">349.02126848 259.08523433 509.83218168 259.08523433</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">86.31299232 267.53522384 360.89189640 267.53522384</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">72.95274971 285.30301181 383.90765475 285.30301181</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">57.23059788 318.82647049 133.67766088 318.82647049</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">165.49619564 319.11457156 523.70654206 319.11457156</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">56.33988814 330.37593621 284.63894658 330.37593621</stroke>
+    </layer>
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="20"/>
diff --git a/articles/Poisson distribution - Wikipedia/Poisson distribution - Wikipedia.xopp.xml b/articles/Poisson distribution - Wikipedia/Poisson distribution - Wikipedia.xopp.xml
index 0f7ea8d..04ffd0a 100644
--- a/articles/Poisson distribution - Wikipedia/Poisson distribution - Wikipedia.xopp.xml	
+++ b/articles/Poisson distribution - Wikipedia/Poisson distribution - Wikipedia.xopp.xml	
@@ -114,11 +114,26 @@
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="8"/>
-    <layer/>
+    <layer>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">84.08988259 757.74443193 239.49238184 757.74443193</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">259.73749334 754.02504661 321.90120889 754.02504661</stroke>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">339.24910112 754.85927235 541.91642347 754.85927235</stroke>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">64.70897328 769.66974432 142.59218235 769.66974432</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#000000ff" width="1.41000000" fill="255">154.97061990 775.62627619 284.50130927 775.62627619</stroke>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">293.69318182 769.19434981 543.84969993 769.19434981</stroke>
+      <stroke tool="highlighter" color="#00c0ff7f" width="8.50000000" fill="128">62.82126687 784.42601984 123.10668082 784.42601984</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">147.09949840 785.78477339 286.16144797 785.78477339</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">493.77890847 782.47852672 518.16128817 783.67778431</stroke>
+      <stroke tool="highlighter" color="#ffff007f" width="8.50000000" fill="128">66.17806175 800.67937678 441.73055814 800.67937678</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">452.69398082 806.79515492 532.95531889 806.79515492</stroke>
+    </layer>
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="9"/>
-    <layer/>
+    <layer>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">65.60480291 50.46844482 418.14186508 50.46844482</stroke>
+      <stroke tool="pen" ts="0" fn="" color="#00c0ffff" width="1.41000000" fill="255">81.62250866 75.63201904 279.84598850 75.63201904</stroke>
+    </layer>
   </page>
   <page width="596.00000000" height="842.00000000">
     <background type="pdf" pageno="10"/>