urbanecm@notebook  ~
$ curl 'https://en.wikipedia.org/api/rest_v1/data/citation/mediawiki/https%3A%2F%2Fwww.idnes.cz%2Fekonomika%2Fdomaci%2Feet-treti-vlna-remeslnici.A190916_152909_ekonomika_fih?action=query&format=json' && echo
{"type":"https://mediawiki.org/wiki/HyperSwitch/errors/unknown_error","method":"get","uri":"/en.wikipedia.org/v1/data/citation/mediawiki/https%3A%2F%2Fwww.idnes.cz%2Fekonomika%2Fdomaci%2Feet-treti-vlna-remeslnici.A190916_152909_ekonomika_fih"}
urbanecm@notebook  ~
$ curl 'https://en.wikipedia.org/api/rest_v1/data/citation/mediawiki/978-80-7442-061-0?action=query&format=json' && echo
{"type":"https://mediawiki.org/wiki/HyperSwitch/errors/not_found","title":"Not found.","method":"get","uri":"/en.wikipedia.org/v1/data/citation/mediawiki/978-80-7442-061-0"}
urbanecm@notebook  ~
$ curl 'https://en.wikipedia.org/api/rest_v1/data/citation/mediawiki/978-80-7362-538-2?action=query&format=json' && echo
{"type":"https://mediawiki.org/wiki/HyperSwitch/errors/not_found","title":"Not found.","method":"get","uri":"/en.wikipedia.org/v1/data/citation/mediawiki/978-80-7362-538-2"}
urbanecm@notebook  ~
$