diff --git a/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.en.md b/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.en.md
new file mode 100644
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+++ b/12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.en.md
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+---
+title: Cylindrical coordinates
+published: true
+routable: false
+visible: false
+---
+
+
+<!--caligraphie de l'intégrale double curviligne-->
+$`\def\oiint{\displaystyle\mathop{{\iint}\mkern-18mu \scriptsize \bigcirc}}`$
+$`\def\Ltau{\Large{\tau}\normalsize}`$
+$`\def\Sopen{\mathscr{S}_{\smile}}`$
+$`\def\Sclosed{\mathscr{S}_{\displaystyle\tiny\bigcirc}}`$
+$`\def\Ssclosed{\mathscr{S}_{\scriptsize\bigcirc}}`$
+$`\def\PSopen{\mathscr{S}_{\smile}}`$
+$`\def\PSclosed{\mathscr{S}_{\displaystyle\tiny\bigcirc}}`$
+
+!!!! *CURSO EN CONSTRUCCIÓN :* <br>
+!!!! *Not published, not visible, not yet approved*<br>
+!!!! work document only for the pedagogical team.
+
+
+<!--MétaDonnée : INSAT-1°année_-->
+
+Main Part to be done