International law exists only in textbooks on international law. Albert Einstein
It is one of the more striking generalizations of biochemistry - which surprisingly is hardly ever mentioned in the biochemical textbooks - that the twenty amino acids and the four bases, are, with minor reservations, the same throughout Nature. Francis Crick
Instructing in cures, therapists always recommend that "each case be individualized." If this advice is followed, one becomes persuaded that those means recommended in textbooks as the best, means perfectly appropriate for the template case, turn out to be completely unsuitable in individual cases. Anton Chekhov
There is no such thing as a normal period of history. Normality is a fiction of economic textbooks. Joan Robinson
Freely licensed textbooks are the next big thing in education. Jimmy Wales
I may be only a fish and chip shop lady, but some of these economists need to get their heads out of the textbooks and get a job in the real world. I would not even let one of them handle my grocery shopping. Pauline Hanson