Complex sentence: Peter Lang is an international academic publisher specializing in the humanities and social sciences which has its headquarters in Pieterlen and Bern, Switzerland, with publishing houses located in Bern, Brussels, Frankfurt am Main, New York, Oxford, Vienna and Warsaw.
Split into simpler sentences: Peter Lang is an international academic publisher specializing in the humanities and social sciences. The global publishing group has its headquarters in Pieterlen and Bern, Switzerland, with publishing houses located in Bern, Brussels, Frankfurt am Main, New York, Oxford, Vienna and Warsaw.