diff --git a/README.md b/README.md
index 5301f51..b7980d6 100644
--- a/README.md
+++ b/README.md
@@ -76,13 +76,19 @@ The following examples show case the ability of this package:
 # Citation
 This package was created as part of scientific work. Please consider citing it :)
 ```bibtex
-@misc{wechsler2024wave,
-      title={Wave optical model for tomographic volumetric additive manufacturing}, 
-      author={Felix Wechsler and Carlo Gigli and Jorge Madrid-Wolff and Christophe Moser},
-      year={2024},
-      eprint={2402.06283},
-      archivePrefix={arXiv},
-      primaryClass={physics.optics}
+@article{Wechsler:24,
+author = {Felix Wechsler and Carlo Gigli and Jorge Madrid-Wolff and Christophe Moser},
+journal = {Opt. Express},
+keywords = {3D printing; Computed tomography; Liquid crystal displays; Material properties; Ray tracing; Refractive index},
+number = {8},
+pages = {14705--14712},
+publisher = {Optica Publishing Group},
+title = {Wave optical model for tomographic volumetric additive manufacturing},
+volume = {32},
+month = {Apr},
+year = {2024},
+url = {https://opg.optica.org/oe/abstract.cfm?URI=oe-32-8-14705},
+doi = {10.1364/OE.521322},
 }
 ```
 
diff --git a/docs/src/assets/mu_spatially.png b/docs/src/assets/mu_spatially.png
new file mode 100644
index 0000000..2414d82
Binary files /dev/null and b/docs/src/assets/mu_spatially.png differ
diff --git a/docs/src/assets/mu_spatially_backprojected.png b/docs/src/assets/mu_spatially_backprojected.png
new file mode 100644
index 0000000..ceade9d
Binary files /dev/null and b/docs/src/assets/mu_spatially_backprojected.png differ
diff --git a/docs/src/geometries.md b/docs/src/geometries.md
index 79c0fe4..72a9c19 100644
--- a/docs/src/geometries.md
+++ b/docs/src/geometries.md
@@ -92,3 +92,23 @@ simshow(projected_exp)
 ![](../assets/parallel_geometry_mu.png)
 
 
+### Spatially Varying Absorption
+
+The ray gets some attenuation with `exp(-μ*x)` where `μ` varies spatially.
+To represent this spatial variation, we can simply use an array for μ.
+
+```julia
+μ = 0.5 .* box((N, N), (2, 50));
+
+simshow(μ)
+```
+![](../assets/mu_spatially.png)
+
+
+```julia
+projected_1 = backproject(sinogram, angles, μ=μ);
+projected_2 = backproject(sinogram, angles .+ π / 4, μ=μ);
+
+[simshow(projected_1) simshow(projected_2)]
+```
+![](../assets/mu_spatially_backprojected.png)
diff --git a/examples/3_spatially_varying_absorption.jl b/examples/3_spatially_varying_absorption.jl
index 410663e..23946e0 100644
--- a/examples/3_spatially_varying_absorption.jl
+++ b/examples/3_spatially_varying_absorption.jl
@@ -102,6 +102,54 @@ problem = OptimizationProblem(opt_fun, init0, angles);
 # ╔═╡ 5f5fb511-4b55-43bb-b8ac-f520e8b3bbc7
 simshow(res6)
 
+# ╔═╡ e6b5f0b8-e4c4-425a-905d-3678396d4dcc
+md"# 6 Scratch"
+
+# ╔═╡ 370d11ad-3b75-4013-8a1d-9439f1bf69b2
+angles2 = [0]
+
+# ╔═╡ 8909b583-1674-49eb-a17e-efe01cfb2154
+N = 200
+
+# ╔═╡ cc8c8da2-18a8-406e-9b22-b8bfa4b76c48
+sinogram2 = zeros((N - 1, length(angles2)))
+
+# ╔═╡ 775543bb-7c6d-46d5-91e1-cbcd980d22d5
+sinogram2[1:5:end] .= 1
+
+# ╔═╡ a97b5c18-921c-422c-a632-58b883f2e89c
+geometry_parallel = RadonParallelCircle(N, -(N-1)÷2:(N-1)÷2)
+
+# ╔═╡ 950f65be-8d23-4b97-ae39-821c48d86ea5
+projection_parallel = backproject(sinogram2, angles2; geometry=geometry_parallel);
+
+# ╔═╡ b63b4b08-0a57-4685-83d6-b0edf0192c28
+simshow(projection_parallel)
+
+# ╔═╡ 2ad8b60a-fa22-4bb2-9e2f-fb819436b229
+geometry_extreme = RadonFlexibleCircle(N, -(N-1)÷2:(N-1)÷2, zeros((199,)))
+
+# ╔═╡ 5addb1be-736c-4d6e-83ed-12e61908acdb
+μ2 = 0.5 .* box((N, N), (2, 50));
+
+# ╔═╡ 3cddcaf4-972e-4e6c-967d-a7ed66c70133
+simshow(μ2)
+
+# ╔═╡ 643831ed-7266-4f1c-ba71-44ebcc44701b
+begin
+	projected_1 = backproject(sinogram2, angles2, μ=μ2);
+	projected_2 = backproject(sinogram2, angles2 .+ π / 4, μ=μ2);
+
+	[simshow(projected_1) simshow(projected_2)]
+end
+
+# ╔═╡ e33dc483-bd00-4806-b319-139ce0df0756
+begin
+	projected_exp2 = backproject(sinogram2, angles2, μ=0.04);
+		
+		simshow(projected_exp2)
+end
+
 # ╔═╡ Cell order:
 # ╠═3e7e2e30-cb85-4eb8-b4f5-b8b19ecade8c
 # ╠═8abe2914-922f-4ea5-8d85-b435a22c897f
@@ -131,3 +179,16 @@ simshow(res6)
 # ╠═fd3a4f13-27c8-4766-9e58-07050aa1db2f
 # ╠═26015d23-e708-4ebc-b718-18bd5104000b
 # ╠═5f5fb511-4b55-43bb-b8ac-f520e8b3bbc7
+# ╠═e6b5f0b8-e4c4-425a-905d-3678396d4dcc
+# ╠═370d11ad-3b75-4013-8a1d-9439f1bf69b2
+# ╠═8909b583-1674-49eb-a17e-efe01cfb2154
+# ╠═cc8c8da2-18a8-406e-9b22-b8bfa4b76c48
+# ╠═775543bb-7c6d-46d5-91e1-cbcd980d22d5
+# ╠═a97b5c18-921c-422c-a632-58b883f2e89c
+# ╠═950f65be-8d23-4b97-ae39-821c48d86ea5
+# ╠═b63b4b08-0a57-4685-83d6-b0edf0192c28
+# ╠═2ad8b60a-fa22-4bb2-9e2f-fb819436b229
+# ╠═5addb1be-736c-4d6e-83ed-12e61908acdb
+# ╠═3cddcaf4-972e-4e6c-967d-a7ed66c70133
+# ╠═643831ed-7266-4f1c-ba71-44ebcc44701b
+# ╠═e33dc483-bd00-4806-b319-139ce0df0756