A recent American Psychologist article on teaching (Gurung et al., 2016) stressed the importance of fostering integration across topic areas. A current trend in publishing and marketing of textbooks is creating pressure that makes this goal harder to implement. The trend is offering custom tailoring of online texts by adopters, letting instructors assign some sections and make other sections unavailable to students. To permit this option, textbook publishers now insist that authors not cross-reference anywhere, so that no instructor will face the possibility of a student looking for material that has not been assigned and thus does not exist. Ironically, this pressure from publishers actively impedes conceptual integration in our textbooks.