diff --git a/ecological_assessment/doc/content/additional.md b/ecological_assessment/doc/content/additional.md
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index 0000000000000000000000000000000000000000..38eacb631807fc02c10e0eace536f487491de004
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+# Additional information {#additional}
diff --git a/ecological_assessment/doc/content/tutorial.md b/ecological_assessment/doc/content/tutorial.md
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+# Tutorials
+@note The idea would be to explain here how developer can extend e.g. for a new strategies and/or new methods within the standard strategy.
+
+E.g.
+- @subpage tutorial_new_strategy
+- @subpage tutorial_new_method_in_standard_strategy
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diff --git a/ecological_assessment/doc/content/tutorial_method_extension.md b/ecological_assessment/doc/content/tutorial_method_extension.md
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index 0000000000000000000000000000000000000000..9a95865cb7b5e8f67ca05cb9f8d4f65d20bab79f
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+++ b/ecological_assessment/doc/content/tutorial_method_extension.md
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+# Tutorial standard strategy extension {#tutorial_new_method_in_standard_strategy}
+@note The idea is to explain how the standard strategy can be extended by a new method
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diff --git a/ecological_assessment/doc/content/tutorial_strategy_extension.md b/ecological_assessment/doc/content/tutorial_strategy_extension.md
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index 0000000000000000000000000000000000000000..1ea123cdbc3d593f2fb38c96b86a594e75a240c8
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+++ b/ecological_assessment/doc/content/tutorial_strategy_extension.md
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+# Tutorial strategy extension {#tutorial_new_strategy}
+Idea is to provide a step by step appraoch how to extend this module by another strategy
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diff --git a/propulsion_design/doc/content/additional.md b/propulsion_design/doc/content/additional.md
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index 0000000000000000000000000000000000000000..7f61c7b57fbec4c0cca6a99cacb6d289e17ec2f8
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+++ b/propulsion_design/doc/content/additional.md
@@ -0,0 +1,4 @@
+# Additional information {#additional}
+Here, you can find additional documentation on specific comments on the code:
+- @subpage propulsion
+- @subpage technology_factors_mass
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diff --git a/propulsion_design/doc/content/tutorial.md b/propulsion_design/doc/content/tutorial.md
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index 0000000000000000000000000000000000000000..26750634576e39cee7b049aa94a0b739567ee81a
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+++ b/propulsion_design/doc/content/tutorial.md
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+# Tutorials
+@note The idea would be to explain here how developer can extend e.g. for a new fidelity and/or a new engine type.
+
+E.g.
+- @subpage tutorial_fidelity_extension
+- @subpage tutorial_engine_extension
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diff --git a/propulsion_design/doc/content/tutorial_engine_extension.md b/propulsion_design/doc/content/tutorial_engine_extension.md
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index 0000000000000000000000000000000000000000..0ce81dc68b20b2479f6e5d98a3d08cc3fbab5a61
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+++ b/propulsion_design/doc/content/tutorial_engine_extension.md
@@ -0,0 +1,2 @@
+# Tutorial engine extension {#tutorial_engine_extension}
+@note The idea is explain e.g. what an engine deck is (is just shortly mentioned in on main page), how to create an engine deck in Gasturb or research an empirical estimation of a new engine type
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diff --git a/propulsion_design/doc/content/tutorial_fidelity_extension.md b/propulsion_design/doc/content/tutorial_fidelity_extension.md
new file mode 100644
index 0000000000000000000000000000000000000000..5e1c9e2845ad9ff9d15a68235a6a278f8f98075a
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+++ b/propulsion_design/doc/content/tutorial_fidelity_extension.md
@@ -0,0 +1,2 @@
+# Tutorial fidelity extension {#tutorial_fidelity_extension}
+Idea is to provide a step by step appraoch how to extend this model by another fidelity
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