For me Dessin d'Enfants by Alexandre Grothendieck is the more concrete research work he has done  . I would like to know if there are others. When he was teaching at Montpellier University (during the 1970's), he thaught the first year students a course on polygons (drawing, computing, ...)  . The results (notes) were good  , but the university establishment did not recocnize them  .

For me "Dessin d'Enfants" by Alexandre Grothendieck is the more concrete research work he has done. I would like to know if there are others.

When he was teaching at Montpellier University (during the 1970's), he taught the first year students a course on polygons (drawing, computing, ...). The results (notes) were good, but the university establishment did not recognize them.