Works in a near identical way to the Select Box Link field, except you can choose whether to display the field as a select box or an autocomplete input.
An extension of Symphony's Select Box Link Field which adds the option to display the field as an autocomplete input field.
Upload the /referencelink folder to your Symphony /extensions folder.
Enable it by selecting the "Field: Reference Link", choose Enable from the with-selected menu, then click Apply.
You can now add the "Reference Link" field to your sections.