Complex sentence: S. Rajendu is the author of History of Valluvanad (2012) and History of Nedunganad (2012), considered as a paradigm shift in the History of Kerala.
Split into simpler sentences: S. Rajendu is the author of History of Valluvanad (2012) and History of Nedunganad (2012). These books are considered as a paradigm shift in the History of Kerala.