"some time previously" is correct and usable in written English.
You can use this phrase to refer to an earlier period of time. For example: "Some time previously, I had gone to the store to buy some groceries."
She heard nothing until 2009 when she was told her case had been refused some time previously.
Ig's major quandary is presumably whether to use the horns to track down the murderer and rapist who killed his girlfriend, Merrin Williams, some time previously.
Fanuc has been researching the use of reinforcement learning for some time, previously working with a Japanese company called Preferred Networks (see "Factory Robot Learns a New Job Overnight").
Numerous decisions would have been referred in the tension but both teams had used their one review some time previously, although the umpires called for a replay to determine Kyle Mills had been run out with five still needed.
The addition of the 4S to the list was pointed out earlier by The Next Web, although it's not clear whether the 4S models were added today or some time previously.
Rimmer is again a hologram, Holly is offline, and Lister is mourning Kochanski, lost to him out of an airlock some time previously.
Therefore, most emergency physicians continue efforts to resuscitate for some time, as previously indicated.
The company has been on the block for some time, having previously tried to work out a deal with Google which fell through.
AMC has been a thorn in MoviePass's side for some time, having previously threatened legal action, which it said devalued the movie-going experience.
He definitely didn't seem depressed right before his death, nor for a long time previously.
Content for the session is standardized, reducing the extensive prep time previously required.
