update README

README.md

@@ -9,6 +9,23 @@ Furtheremore, we will discuss how to:
 3. Visualise the trajectory from simulations.
 4. Analyse the output from simulations.
 
+Please if you use any of the codes here, do not forget to cite this repository and the  corresponding papers in the following links:
+
+[bead-spring polymer with Topo2](https://academic.oup.com/nar/article/50/8/4659/6574672)
+
+[dsDNA implementation](https://pubs.rsc.org/en/content/articlelanding/2016/sm/c6sm01859a)
+
+[dsDNA melting](https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.118002)
+
+[dsDNA supercoling dynamics](https://www.pnas.org/doi/10.1073/pnas.1905215118)
+
+[oxDNA twist, roll, tilt deformations and dynamics](https://pubs.rsc.org/en/content/articlelanding/2021/sm/d0sm01812k)
+
+[oxDNA implementation into LAMMPS](https://link.springer.com/article/10.1140/epje/i2018-11669-8)
+
+[DNA nanostar with oxDNA](https://arxiv.org/abs/2202.06331)
+
+
 ## Requirements
 In this section you will find the software neccessary for this tutorial and instructions on how to install it. The tutorial assumes that a LAMMPS executable  called **lmp\_mpi\_29Sep2021** exist into this folder (see below for installation).