Working steps to remove this line from your blog,
Step 1. Log in to your Dashboard,
go to Template > Edit
HTML
Step 2. Click anywhere inside the code area and press
the (CTRL + F) keys to open the Blogger' search box
Step 3. Type or paste the following tag inside the
search box then hit Enter to find it:
</head>
Step 4. Just above </head> add this code:
<style>
#Attribution1...
