diff --git a/src/dedicated-workers/libs/lambert.ts b/src/dedicated-workers/libs/lambert.ts
index 995179c..27e3d6b 100644
--- a/src/dedicated-workers/libs/lambert.ts
+++ b/src/dedicated-workers/libs/lambert.ts
@@ -1,6 +1,31 @@
 // Direct port to TypeScript of ESA's Lambert problem solver, simplified to the case of 0 revolutions.
 // from : https://github.com/esa/pykep/blob/master/src/lambert_problem.cpp
 
+/*****************************************************************************
+ *   Copyright (C) 2004-2018 The pykep development team,                     *
+ *   Advanced Concepts Team (ACT), European Space Agency (ESA)               *
+ *                                                                           *
+ *   https://gitter.im/esa/pykep                                             *
+ *   https://github.com/esa/pykep                                            *
+ *                                                                           *
+ *   act@esa.int                                                             *
+ *                                                                           *
+ *   This program is free software; you can redistribute it and/or modify    *
+ *   it under the terms of the GNU General Public License as published by    *
+ *   the Free Software Foundation; either version 2 of the License, or       *
+ *   (at your option) any later version.                                     *
+ *                                                                           *
+ *   This program is distributed in the hope that it will be useful,         *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ *   GNU General Public License for more details.                            *
+ *                                                                           *
+ *   You should have received a copy of the GNU General Public License       *
+ *   along with this program; if not, write to the                           *
+ *   Free Software Foundation, Inc.,                                         *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.               *
+ *****************************************************************************/
+
 /**
  * Solves the Lambert's problem considering 0 revolutions and prograde direction only.
  * @param r1vec The start position in space
@@ -184,4 +209,4 @@ function hypergeometricF(z: number, tol: number)
         j++;
     }
     return Sj;
-}
\ No newline at end of file
+}