add literature links to the readme

Readme.md

@@ -12,6 +12,26 @@ an application for performing [Monte Carlo] simulations of ion implantation.
 * The binary (statically linked) from the [Fortran] code is also included.
 * [RPM] and [DEB] packages are also included.
 
+Further information can be found in the following publications:
+
+- J. P. Biersack and W. Eckstein,
+  <i>Sputtering studies with the Monte Carlo program TRIM.SP</i>,
+  Appl. Phys. A <b>34</b> (2), 73-94 (1984).
+  <https://doi.org/10.1007/BF00614759>
+- W. Eckstein,
+  <i>Computer Simulation of Ion-Solid Interactions</i>,
+  Springer Series in Materials Science Vol. 10
+  (Springer-Verlag, Berlin, Heidelberg, 1991).
+  <https://doi.org/10.1007/978-3-642-73513-4>
+- W. Eckstein,
+  <i>Backscattering and sputtering with the Monte-Carlo program TRIM.SP</i>,
+  Radiat. Eff. Defects Solids <b>130-131</b> (1), 239-250 (1994).
+  <https://doi.org/10.1080/10420159408219787>
+- E. Morenzoni et al.,
+  <i>Implantation studies of keV positive muons in thin metallic layers</i>,
+  Nucl. Instrum. Methods Phys. Res., Sect. B <b>192</b> (3), 245-266 (2002).
+  <https://doi.org/10.1016/S0168-583X(01)01166-1>
+
 ### Supported platforms ###
 
 * [Linux]