Couple of items of Byzantine/Normans in the South interest by George Theotokis recently recommended by Academia
https://www.academia.edu/2401450/_The_campaigns_of_the_Norman_Dukes_of_Southern_Italy_and_Sicily_to_Byzantium_in_the_years_between_1071-1108_A.D_PhD_University_of_Glasgow_2010_?email_work_card=title
This is his PhD thesis, which formed the basis of a book published by Boydell and Brewer.
https://www.academia.edu/2401445/_Rus_Varangian_and_Frankish_mercenaries_in_the_service_of_the_Byzantine_Emperors_9th_11th_c._Numbers_Organisation_and_Battle_Tactics_in_the_operational_theatres_of_Asia_Minor_and_the_Balkans_Byzantina_Symmeikta_22_2012_pp._126-156