Complex sentence: In Birka, a Völva and a warrior were once buried together and above them, a spear was positioned in order to dedicate the dead couple to Odin.
Split into simpler sentences: In Birka, a Völva and a warrior were once buried together. Harrison & Svensson 2007:62 Above them, a spear had been positioned in order to dedicate the dead couple to Odin.