# Multiple bib files not compiling

I have all my references separated into multiple .bib files. When I try to compile my document - only the first bib file is used and the others are ignored. Here is a basic example with just two bib files:

\documentclass[]{article}

\title{Agricultural Crop Characterization using Spatio-temporal Scattering Properties of Polarimetric SAR data and a Deep Learning Framework.}
\author{Shauank De}
\date{}

\begin{document}

\maketitle

\input{0_Problem_Statement}
\input{1_introduction}
\input{2_Science}
\input{3_Methodology}

\section{Science Background}

\bibliographystyle{IEEEtran}
\bibliography{References/Proposal_Agri , References/polsar}
\end{document}


It only pulls information from whichever bib file is listed first. I even tried using sharelatex - and I have the same result.

Here is my log file:

Process started: bibtex.exe "SD_Agri_2017"

This is BibTeX, Version 0.99d (MiKTeX 2.9)
The top-level auxiliary file: SD_Agri_2017.aux
The style file: IEEEtran.bst
White space in argument---line 11 of file SD_Agri_2017.aux
: \bibdata{References/Proposal_Agri,
:                                    References/polsar}
I'm skipping whatever remains of this command
Database file #1: References/Proposal_Agri.bib
Repeated entry---line 38 of file References/Proposal_Agri.bib
: @article{zhang2009mapping
:                          ,
I'm skipping whatever remains of this entry
Warning--I didn't find a database entry for "da2008land"
Warning--I didn't find a database entry for "lee2004unsupervised"
-- IEEEtran.bst version 1.14 (2015/08/26) by Michael Shell.
-- http://www.michaelshell.org/tex/ieeetran/bibtex/
-- See the "IEEEtran_bst_HOWTO.pdf" manual for usage information.
Warning--empty journal in wilkinson2006crop

Done.
(There were 2 error messages)

Process exited normally


Can someone point me to what I am doing wrong?

I discovered the source of the error. You can't have spaces in the \bibliography{References/Proposal_Agri , References/polsar} command.
The correct command is: \bibliography{References/Proposal_Agri,References/polsar}