Glueck's Firefly pendant hangs from a tree branch in the Beyond the Wall section of The Quarantine Zone, so you have to knock it down. It belonged to Ben Glueck.
Ben Glueck won a 2013 Naughty Dog fan art contest, and the prize was his name on a pendant in the game.
Boston Q.Z. Map
The Boston Q.Z. Map is the first artifact in the game and you cannot miss it: it is already inside Joel's backpack when you pick the bag up off a table in the smuggling tunnel during Beyond the Wall.
Docks Note
The Docks Note is a gripe from one of Robert's smugglers, lying in the big warehouse at Mission Hill Pier where a fishing boat hangs over the loading bay. Look on the right side, against the railing behind a blue trash bin.
Drafting Notice
The Drafting Notice is a FEDRA work order lying in a heap of papers in the Boston slums. After the bus where Malick confronts Joel, walk straight on between a vendor's stall on the left and a canopy on the right; the notice is on the ground at the corner.
Liu's Firefly Pendant
Liu's Firefly pendant is on the body of a dead Firefly in The Cargo section of The Quarantine Zone, right after Ellie joins Joel and Tess. It belonged to Philip Liu.