Complex sentence: From that point onward he used computational methods extensively in his research, which focussed on lower central series of Burnside groups, which he related to problems in other areas including linear algebra and topological sorting of graphs.
Split into simpler sentences: From that point onward he used computational methods extensively in his research, which focussed on lower central series of Burnside groups. He related this problem to problems in other areas of mathematics including linear algebra and topological sorting of graphs.