In computer programming, a weak reference is a reference that does not protect the referenced object from collection by a garbage collector; unlike a strong reference. An object referenced only by weak references is considered unreachable (or weakly reachable) and so may be collected at any time.

Weak Reference
Weak Reference
Weak Reference
The Weak-Reference Interface
Weak Reference and Semantic Incorporation
Weak reference and property denotation. two types of pseudo-incorporated bare nominals
Weak reference and property denotation. two types of pseudo-incorporated bare nominals
Linked Weak Reference Arrays: A Hybrid Approach To Efficient Bulk Finalization
Linked Weak Reference Arrays: A Hybrid Approach To Efficient Bulk Finalization
Weak Reference or the True Semantics of Relative Identity Statements
Phase measurements with weak reference pulses
[R] difference between "external pointer"and "weak reference"
[R] difference between "external pointer"and "weak reference"