Ive got 2 of the shards and i was wondering if someone could tell me the location of the other 2..

The map in Katria's (or whatever her name was) diary show the sites where the shards are.

As far as i remember, the sites were:
Deep Folk Crossing near the western edge of the map.
Storage builiding near Mzulft (the ruin related to the College questline).
And in the ruin near Uttering Hills Cave west of Windhelm, whatever it's name was

From the Wiki: http://www.uesp.net/wiki/Skyrim:Lost_to_the_Ages

Katria will tell you to find the other shards with help from her journal, and then she'll meet you at each location. Travel to http://www.uesp.net/wiki/Skyrim:Raldbthar for the second, http://www.uesp.net/wiki/Skyrim:Mzulft for the third, and http://www.uesp.net/wiki/Skyrim:Deep_Folk_Crossing for the last piece.

• The shard at Raldbthar is located in a small room near the end of the ruin, right across from the elevator leading out. (For a quick run if you've cleared it, enter through the elevator.)
  
• The next shard in a http://www.uesp.net/wiki/Skyrim:Dwarven_Storeroom directly south of Mzulft. There are a few leveled chests, and the shard directly ahead when you enter.
  
• The last shard is located at http://www.uesp.net/wiki/Skyrim:Deep_Folk_Crossing a Dwarven bridge located northeast of http://www.uesp.net/wiki/Skyrim:Markarth and slightly north of http://www.uesp.net/wiki/Skyrim:Bthardamz. Go across the bridge and up a small path to find a raised dais with the shard on the far side.

thanks