diff --git a/cheatsheets/pdftk b/cheatsheets/pdftk
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index 0000000..d4d2ec2
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+++ b/cheatsheets/pdftk
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+# Concatenate all pdf files into one:
+pdftk *.pdf cat output all.pdf
+
+# Concatenate pages 1 to 5 of first.pdf with page 3 of second.pdf
+pdftk A=fist.pdf B=second.pdf cat A1-5 B3 output new.pdf
+