"Edge gluing"?

I'm contemplating tackling Ken West's excellent X-15A-2 and in reading through his instructions, he says various parts (such as the pieces that make up the chines) should be "edge glued" to assemble them. I've been modeling for years but I'm unfamiliar with the term.

I get what it means -- glue the edges -- but Ken says nothing about joining strips, and I'm uncertain how just gluing two or more pieces together at the edges, without any kind of backing, provides the strength necessary for shaping the pieces, etc.

Is there some technique I need to know, or should I just make joining strips?