update refs style

docs/src/references.bib

@@ -47,31 +47,31 @@ @article{Kassam-Trefethen-2005
 }
 
 @techreport{Carpenter-Kennedy-1994,
-  author = {Carpenter, M. H. and Kennedy, C. A.},
-  title = {Fourth-order $2N$-storage Runge--Kutta schemes},
-  institution = {National Aeronautics and Space Administration},
-  year = {1994},
-  number = {NASA TM-109112},
-  address = {NASA Langley Research Center, Hampton, VA},
-  url = {https://ntrs.nasa.gov/api/citations/19940028444/downloads/19940028444.pdf}
+    author = {Carpenter, M. H. and Kennedy, C. A.},
+    title = {Fourth-order $2N$-storage Runge--Kutta schemes},
+    institution = {National Aeronautics and Space Administration},
+    year = {1994},
+    number = {NASA TM-109112},
+    address = {NASA Langley Research Center, Hampton, VA},
+    url = {https://ntrs.nasa.gov/api/citations/19940028444/downloads/19940028444.pdf}
 }
 
 @article{Toner-Tu-1995,
-  title = {Long-Range order in a two-dimensional dynamical $\mathrm{XY}$ model: How birds fly together},
-  author = {Toner, J. and Tu, Y.},
-  journal = {Physical Review Letters},
-  volume = {75},
-  issue = {23},
-  pages = {4326-4329},
-  year = {1995},
-  doi = {10.1103/PhysRevLett.75.4326},
+    title = {Long-Range order in a two-dimensional dynamical $\mathrm{XY}$ model: How birds fly together},
+    author = {Toner, J. and Tu, Y.},
+    journal = {Physical Review Letters},
+    volume = {75},
+    issue = {23},
+    pages = {4326-4329},
+    year = {1995},
+    doi = {10.1103/PhysRevLett.75.4326},
 }
 
 @book{Chaikin-Lubensky-1995,
-  title = {Principles of condensed matter physics},
-  author = {Chaikin, P. M. and Lubensky, T. C.},
-  publisher = {Cambridge University Press},
-  place = {Cambridge},
-  doi = {10.1017/CBO9780511813467},
-  year = {1995}
+    title = {Principles of condensed matter physics},
+    author = {Chaikin, P. M. and Lubensky, T. C.},
+    publisher = {Cambridge University Press},
+    place = {Cambridge},
+    doi = {10.1017/CBO9780511813467},
+    year = {1995}
 }