Many Arab coins are found in Norse hoards in Russia along the Volga route (and probably further west) - archeologists actually use these to date the burials and chart the progression of Viking settlements along Russian rivers. While these dirhams could have been due to the Vikings trading via some intermediaries we do happen to know that the Norsemen mounted several raids down the Volga into the Caspian between the 9th and the 11th centuries. Armenian, Arab and Persian writers mention them in their works like Ibn Isfandiyar's History of Tabaristan or Al-Masudi's Meadows of Gold and Mines of Gems. Most of these raids were mounted by the Rus' - that is, the Vikings who settled in what is now Russia and Ukraine (hence the word Russia). But there was also at least one expedition that sailed all the way from Sweden that is documented in a [saga] (http://www.northvegr.org/sagas%20annd%20epics/legendary%20heroic%20and%20imaginative%20sagas/old%20heithinn%20tales%20from%20the%20north/051.html) and a group of rune stones commemorating various warriors who did not return from the Land of Saracenes. So yes, there's plenty of records.