http://oracle-base.com/articles/misc/using-ref-cursors-to-return-recordsets.php
http://oracle-base.com/articles/8i/complex-recordsets.php
http://www.martinbulinski.de/plsql-tutorial/dynamisches-sql-mit-ref-cursor
https://msdn.microsoft.com/de-de/library/bw9eczdk%28v=vs.110%29.aspx
http://sql-plsql.blogspot.de/2007/05/oracle-plsql-ref-cursors.html !!!
http://www.cmoser.de/blog-archiv.html?month=201307
http://www.java2s.com/Tutorial/Oracle/0500__Cursor/Definerefcursorvariable.htm
http://www.asktheoracle.net/what-is-ref-cursor.html
http://www.mathworks.com/matlabcentral/newsreader/view_thread/260796
http://www.akadia.com/services/ora_return_result_set.html
http://www.toadworld.com/platforms/oracle/w/wiki/1856.ref-cursor-type.aspx
http://www-01.ibm.com/support/knowledgecenter/SSEPGG_9.7.0/com.ibm.db2.luw.apdv.plsql.doc/doc/c0053892.html
http://www.morganslibrary.org/reference/plsql/ref_cursors.html
http://www.databasedesign-resource.com/ref-cursor.html