If this is in the underlying query then you need to use the form references.
Code:
SELECT [tblReference].[ReferenceID], [tblReference].[BusinessID], [tblReference].[ReferenceName]
FROM tblReference
WHERE BusinessID = Forms!YourFormName!TxtBoxControlBusinessID ORDER BY [ReferenceName];
If you are building it VBA then your concatenation is all out of kilter ;
Code:
SELECT [tblReference].[ReferenceID], [tblReference].[BusinessID], [tblReference].[ReferenceName]
FROM tblReference WHERE BusinessID = " & Me.BusinessID & " ORDER BY [ReferenceName]"