> For the complete documentation index, see [llms.txt](https://blackboard.crashkonijn.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://blackboard.crashkonijn.com/examples/13_blackboard_references.md).

# 13 Blackboard References

This example shows you how to reference another blackboard from a blackboard.

These files can be found in the /Examples/\[example] and /Blackboards/Examples folders.

## SourceBlackboard.cs

```csharp
using CrashKonijn.RabbitBlackboard.Contracts;

namespace CrashKonijn.BlackboardPro.Blackboards.Examples
{
    public partial class SourceBlackboard : BlackboardBehaviour
    {
        private int lowHealth = 50;
    }
}

```

## ReferenceBlackboard.cs

```csharp
using CrashKonijn.RabbitBlackboard.Contracts;

namespace CrashKonijn.BlackboardPro.Blackboards.Examples
{
    public partial class ReferenceBlackboard : BlackboardBehaviour
    {
        private SourceBlackboard _sourceBlackboard;

        private int health;

        private static bool isLowHealth(SourceBlackboard.Signals.LowHealth lowHealth, Signals.Health health) => health.Value < lowHealth.Value;
    }
}

```

## DoubleReferenceBlackboard.cs

```csharp
using CrashKonijn.RabbitBlackboard.Contracts;

namespace CrashKonijn.BlackboardPro.Blackboards.Examples
{
    public partial class DoubleReferenceBlackboard : BlackboardBehaviour
    {
        private ReferenceBlackboard referenceBlackboard;

        private static bool isAlive(ReferenceBlackboard.Signals.Health health) => health.Value > 0;
        private static bool isHighHealth(ReferenceBlackboard.Signals.Health health, SourceBlackboard.Signals.LowHealth lowHealth) => health.Value > lowHealth.Value;
    }
}

```