Complex sentence: In addition to including the rare 7 edits of "Fame" and "Golden Years", the compilation contains unique edits of "Life on Mars?" and "Diamond Dogs", ostensibly to allow all 16 tracks to fit on one LP.
Split into simpler sentences: In addition to including the rare 7 edits of "Fame" and "Golden Years," the compilation contains unique edits of "Life On Mars?" and "Diamond Dogs". It is assumed that these edits were made to allow all 16 tracks to fit on one LP.