How to install autoconf

I need to install Tesseract, that need to install autoconf automake libtool, However I got the error as follows:

sahu@sahu-desktop:/$ sudo apt-get install autoconf
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package autoconf is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'autoconf' has no installation candidate

So please help me.

Make sure you have enabled all necessary repositories. Do a 'How do I enable repository' search on the site. After enabling the repositories, open a terminal and use these commands to install autoconf

sudo apt-get update
sudo apt-get install autoconf

Your error messege suggested that, you have disabled repository.

Autoconf is a GPLv2-licensed package of macros that produces a shell script "configure" to generate a Makefile and config header for a project. The configuration scripts produced by Autoconf are self-contained, so the users of your project do not need Autoconf, M4, or perl to run configure.¹

To download the latest version click here, and for instructions on how to install, click here.

You need to Extract Autoconf, Build it, and Install Autoconf (must be root user)

Another way is to install from the Ubuntu Software Center,

Also To download and install click the image below.

You can also follow Anwar's answer.

^{1Source:Autoconf}