Merge pull request #145 from rcaneill/patch-2

Add citation in README.md

README.md

@@ -58,6 +58,21 @@ C99 complex data type used in original GSW-C.
 
 To test, after installation, run "pytest" from the source directory.
 
+## Citation
+
+If you use GSW-Python, please cite: McDougall, T.J. and P.M. Barker, 2011: Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox, 28pp., SCOR/IAPSO WG127, ISBN 978-0-646-55621-5
+
+```bibtex
+@book{mcdougall2011getting,
+  author = {McDougall, T. J. and Barker, P. M.},
+  title = {Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox},
+  year = {2011},
+  pages = {28},
+  publisher = {SCOR/IAPSO WG127},
+  isbn = {978-0-646-55621-5}
+}
+```
+
 ## Note for xarray users
 
 A wrapper around gsw called [gsw-xarray](https://github.com/DocOtak/gsw-xarray) exists for xarray.