diff --git a/lepaper/Tmatrix.bib b/lepaper/Tmatrix.bib
index 3869c17..692bc00 100644
--- a/lepaper/Tmatrix.bib
+++ b/lepaper/Tmatrix.bib
@@ -974,4 +974,42 @@ Recent progress in metasurface designs fueled by advanced-fabrication techniques
   file = {/u/46/necadam1/unix/.mozilla/firefox/6m8fw48s.default/zotero/storage/MEQRS28G/Michael I. Mishchenko, Larry D. Travis, Andrew A. Lacis - Scattering, Absorption, and Emission of Light by Small Particles-Cambridge University Press (2002).djvu}
 }
 
+@article{mackowski_multiple_2011,
+  series = {Polarimetric {{Detection}}, {{Characterization}}, and {{Remote Sensing}}},
+  title = {A Multiple Sphere {{T}}-Matrix {{Fortran}} Code for Use on Parallel Computer Clusters},
+  volume = {112},
+  issn = {0022-4073},
+  abstract = {A general-purpose Fortran-90 code for calculation of the electromagnetic scattering and absorption properties of multiple sphere clusters is described. The code can calculate the efficiency factors and scattering matrix elements of the cluster for either fixed or random orientation with respect to the incident beam and for plane wave or localized-approximation Gaussian incident fields. In addition, the code can calculate maps of the electric field both interior and exterior to the spheres. The code is written with message passing interface instructions to enable the use on distributed memory compute clusters, and for such platforms the code can make feasible the calculation of absorption, scattering, and general EM characteristics of systems containing several thousand spheres.},
+  language = {en},
+  number = {13},
+  urldate = {2019-11-17},
+  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
+  doi = {10.1016/j.jqsrt.2011.02.019},
+  url = {http://www.sciencedirect.com/science/article/pii/S0022407311001129},
+  author = {Mackowski, D. W. and Mishchenko, M. I.},
+  month = sep,
+  year = {2011},
+  keywords = {-matrix method,Multiple sphere scattering,Numerical methods},
+  pages = {2182-2192},
+  file = {/u/46/necadam1/unix/.mozilla/firefox/6m8fw48s.default/zotero/storage/N937G5U7/Mackowski ja Mishchenko - 2011 - A multiple sphere T-matrix Fortran code for use on.pdf;/u/46/necadam1/unix/.mozilla/firefox/6m8fw48s.default/zotero/storage/Q3RU9NXV/S0022407311001129.html}
+}
+
+@misc{xu_fortran_2003,
+  title = {Fortran Codes for Multi-Particle Light-Scattering Calculations},
+  urldate = {2019-11-17},
+  url = {https://scattport.org/files/xu/codes.htm},
+  author = {Xu, Yu-Lin},
+  year = {2003},
+  file = {/u/46/necadam1/unix/.mozilla/firefox/6m8fw48s.default/zotero/storage/9DLVV7ZN/codes.html}
+}
+
+@misc{scattport_multiple_nodate,
+  title = {Multiple {{Particle Scattering}}},
+  urldate = {2019-11-17},
+  journal = {https://scattport.org/index.php/light-scattering-software/multiple-particle-scattering},
+  url = {https://scattport.org/index.php/light-scattering-software/multiple-particle-scattering},
+  author = {ScattPort},
+  file = {/u/46/necadam1/unix/.mozilla/firefox/6m8fw48s.default/zotero/storage/S9YB95Y2/multiple-particle-scattering.html}
+}
+
 
diff --git a/lepaper/intro.lyx b/lepaper/intro.lyx
index 1a8ce3f..8cd1dc8 100644
--- a/lepaper/intro.lyx
+++ b/lepaper/intro.lyx
@@ -291,18 +291,28 @@ a.k.a.
 
 \end_inset
 
-, and it has been implemented previously for a limited subset of problems
-\begin_inset Marginal
-status open
+, and it has been implemented many times in the context of electromagnetics
+ 
+\begin_inset CommandInset citation
+LatexCommand cite
+key "scattport_multiple_nodate"
+literal "false"
 
-\begin_layout Plain Layout
-Refs; list the limitations of available codes?
-\end_layout
+\end_inset
+
+, but usually only as specific codes for limited subsets of problems, such
+ as scattering by clusters of spheres, circular cylinders, or Chebyshev
+ particles 
+\begin_inset CommandInset citation
+LatexCommand cite
+key "mackowski_multiple_2011,mackowski_mstm_2013,xu_fortran_2003"
+literal "false"
 
 \end_inset
 
 .
- 
+ Perhaps the most general MSTMM software with respect to the system geometry
+ has been FaSTMM 
 \begin_inset CommandInset citation
 LatexCommand cite
 key "markkanen_fast_2017,markkanen_fastmm_2017"
@@ -310,18 +320,7 @@ literal "false"
 
 \end_inset
 
- 
-\begin_inset Note Note
-status open
-
-\begin_layout Plain Layout
-TODO přestože blablaba, moc se to nepoužívalo, protože je težké udělat to
- správně.
-\end_layout
-
-\end_inset
-
- 
+, which also a rare example is in this field of a code with a clear licence.
 \end_layout
 
 \begin_layout Standard