diff --git a/application/config/routes.php b/application/config/routes.php
index a255321b2..da3a45f03 100644
--- a/application/config/routes.php
+++ b/application/config/routes.php
@@ -87,22 +87,22 @@ $route['api/frontend/v1/stv/[sS]tudents/(:num)/([A-Z]{2,3})/prestudent/([WS]S[0-
 $route['api/frontend/v1/stv/[sS]tudents/(:num)/([A-Z]{2,3})/prestudent/([WS]S[0-9]{4})/(:any)/(:any)'] = 'api/frontend/v1/stv/Students/getPrestudentsOrgform/$1/$2/$3/$5';
 
 // (studiensemester_kurzbz)/(studiengang_kz)/(semester)/grp/(gruppe)
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/(:num)/grp/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsSpezialgruppe/$1/$2/$3/$4';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/(:num)/grp/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsSpezialgruppe/$1/$2/$3/$4';
 
 // (studiensemester_kurzbz)/(studiengang_kz)[/(semester)[/(verband)[/(gruppe)]]]
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2';
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/(:num)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2/$3';
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/(:num)/(:any)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2/$3/$4';
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/(:num)/(:any)/(:any)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2/$3/$4/$5';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/(:num)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2/$3';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/(:num)/(:any)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2/$3/$4';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/(:num)/(:any)/(:any)'] = 'api/frontend/v1/stv/Students/getStudents/$1/$2/$3/$4/$5';
 
 // (studiensemester_kurzbz)/(studiengang_kz)/(orgform)/(semester)/grp/(gruppe)
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/([A-Z]{2,3})/(:num)/grp/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsOrgformSpezialgruppe/$1/$2/$3/$4/$5';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/([A-Z]{2,3})/(:num)/grp/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsOrgformSpezialgruppe/$1/$2/$3/$4/$5';
 
 // (studiensemester_kurzbz)/(studiengang_kz)/(orgform)[/(semester)[/(verband)[/(gruppe)]]]
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/([A-Z]{2,3})'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3';
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/([A-Z]{2,3})/(:num)'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3/$4';
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/([A-Z]{2,3})/(:num)/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3/$4/$5';
-$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(:any)/([A-Z]{2,3})/(:num)/(:any)/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3/$4/$5/$6';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/([A-Z]{2,3})'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/([A-Z]{2,3})/(:num)'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3/$4';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/([A-Z]{2,3})/(:num)/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3/$4/$5';
+$route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/(-?[0-9]+)/([A-Z]{2,3})/(:num)/(:any)/(:any)'] = 'api/frontend/v1/stv/Students/getStudentsOrgform/$1/$2/$3/$4/$5/$6';
 
 // // (studiensemester_kurzbz)/uid/(uid)
 $route['api/frontend/v1/stv/[sS]tudents/([WS]S[0-9]{4})/uid/(:any)'] = 'api/frontend/v1/stv/Students/getStudent/$1/$2';