DONETSK, April 24. /ITAR-TASS/. The leadership of the recently self-proclaimed Donetsk Peoples Republic plans to hold a referendum simultaneously with east Ukraines Luhansk region, co-chairman of the Donetsk Peoples Republic presidium Denis Pushilin told ITAR-TASS. A referendum will be held no later than on May 11 and it is highly probable that Luhansk will also hold it with us no later than on May 11.