When designing the API, make sure the reference type is documented so callers understand whether they receive a direct copy or an alias.

In special relativity, observers in different reference frames can disagree on the simultaneity of events.

To measure the object's velocity correctly, you must specify the reference frame used for the observations.

I had to visit the reference library because the rare atlases there are non-circulating and cannot be checked out.

When calibrating the telescope's photometry, we observed the reference star whose magnitude had been measured to high precision.

Many university departments maintain small reference libraries for students researching niche topics.

The compiler reported a forward reference when the function was called before it was declared.

When debugging the application, I found a circular reference between two objects that caused a memory leak.

The cache uses a weak reference so the object can still be reclaimed by the garbage collector.

I stored the large image in the cache using a soft reference to allow it to be reclaimed under memory pressure.