Attacking a GAL Report

I was reading an article by Larry Primeaux this morning dealing with the guardian ad litem report in Gateley v. Gateley.  A copy of the article is located here.  This lead me to do some thinking.  How is a guardian ad litem report attacked?  After some thought, I decided a learned treatise attacking under 803(18) of the Mississippi Rules of Evidence is one avenue.  As one chancellor has put it, there is caseload for most any position, and most of it is in Bell on Family Law.  I believe this book could be used as a learned treatise to attack an Albright analysis by a GAL.