Complex sentence: In a volume published in early 1974, Norman predicted that a spacefleet of an Intergalactic Confederation was to land on Earth in December 1974, a date that she soon revised to September 1975, citing ongoing Confederation efforts to prepare humanity for their landing.
Split into simpler sentences: In a volume published in early 1974, Norman predicted that a spacefleet of an Intergalactic Confederation was to land on Earth in December 1974. She soon revised the date to September 1975, citing ongoing Confederation efforts to prepare humanity for their landing.