Most publishers have a “download citation” button on the article pages, but not all of them export in bib format. Looking for an alternative, I learned that Crossref now has a nice feature with which one can get the bibliography entry from the DOI. More info here. Use the following code at the commandline (needs curl installed)

curl -LH "Accept: text/bibliography; style=bibtex" http://dx.doi.org/10.1103/PhysRevLett.112.086802

which returns:

@article{Shanavas_Satpathy_2014, 
title={Electric Field Tuning of the Rashba Effect in the Polar Perovskite Structures},
volume={112}, ISSN={1079-7114}, 
url={http://dx.doi.org/10.1103/PhysRevLett.112.086802}, DOI={10.1103/physrevlett.112.086802}, 
number={8}, 
journal={Physical Review Letters}, 
publisher={American Physical Society (APS)}, author={Shanavas, K. V. and Satpathy, S.}, 
year={2014}, 
month={Feb}}

I wrote a function which can be put in the .bashrc file. It will seperate the entry into multiple lines for readability

doi2bib() { curl -LH "Accept: text/bibliography; style=bibtex" http://dx.doi.org/"$@" | awk '{sub(",",",\n"); gsub("},","},\n"); print $0}'; }

To use it, simply run doi2bib 10.1103/PhysRevLett.112.086802 from the command line.

At this stage there are three problems with this method:

1. The journal abbreviations are not always used
2. The author list is truncated if it is too long
3. For many APS articles page numbers are not returned