What methods do you know for eliminating cyclic references in memory management?

Cyclic references occur when two objects refer to each other, preventing automatic memory deallocation. Methods to eliminate them:

• Using weak references to break the cycle. For example, in Swift:

class A {
    var b: B?
}

class B {
    weak var a: A?
}

• Applying unowned references when the object is guaranteed to exist longer.
• Explicitly nullifying references when finished working with objects.
• Using memory analysis tools (Instruments in Xcode) to detect cycles.