Cross-Referencing Line Numbers in LaTeX

http://seananderson.ca/2013/04/28/cross-referencing-reviewer-replies-in-latex.html

\usepackage[pagewise]{lineno}

And wherever you want to start the line numbers in your document add:

\linenumbers

Now we'll set up two new commands in the preamble. First, create a new command to label your changes:

\newcommand{\R}[1]{\label{#1}\linelabel{#1}}

Then, create a new command to cross-reference your changes:

\newcommand{\lr}[1]{page~\pageref{#1}, line~\lineref{#1}}

Now, say you wanted to revise a sentence to deal with Reviewer comment A1. You can just add something like this within the manuscript:

\R{A1} A sentenced we have revised...

In the reply document, you can reference this change like this::

We have revised the text. Please see \lr{A1}.