The most common and most likely answer to this crossword clue is the 5 letter word WELLS
I've seen this crossword clue in The Guardian
W
E
L
L
S
More clues leading to the result WELLS
Buddy explains!

The straight part
We know that "Writer/sources" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case writer/sources = wells.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does WELLS mean?
WELLS noun- A hole sunk into the ground as a source of water, oil, natural gas or other fluids.
- A place where a liquid such as water surfaces naturally; a spring.
- A small depression suitable for holding liquid or other objects.
- A source of supply.
- A vertical, cylindrical trunk in a ship, reaching down to the lowest part of the hull, through which the bilge pumps operate.
- The cockpit of a sailboat.
- A compartment in the middle of the hold of a fishing vessel, made tight at the sides, but having holes perforated in the bottom to let in water to keep fish alive while they are transported to market.
- A vertical passage in the stern into which an auxiliary screw propeller may be drawn up out of the water.
- A hole or excavation in the earth, in mining, from which run branches or galleries.
- An opening through the floors of a building, as for a staircase or an elevator; a wellhole.
- The open space between the bench and the counsel tables in a courtroom.
- The lower part of a furnace, into which the metal falls.
- A well drink.
- The playfield of Tetris and similar video games, into which the blocks fall.
- In a microtiter plate, each of the small equal circular or square sections which serve as test tubes.
- To issue forth, as water from the earth; to flow; to spring.
- To have something seep out of the surface.