Complex sentence: Under the name Zev Blitzer, he wrote for "Al HaMishmar"; using the name Zev Barak, he had work published in "Yedioth Ahronoth".
Split into simpler sentences: Under the name Zev Blitzer, he wrote for "Al HaMishmar". Using the name Zev Barak, he had work published in "Yedioth Ahronoth".