Sheldon diz isso, mas ele usa o inicialismo quando se apresenta no início da palestra que está apresentando:
Good morning and welcome to Science and Society. I’m Dr. Sheldon Cooper, BS, MS, MA, PhD, and ScD. OMG, right? Perhaps that joke was a little too hippie-dippy for this crowd. All right then, we’ll begin with opening remarks. Miss Rostenkowski, would you like to start us off by discussing your assessment of science’s responsibility to society?
Como as notas da Wikipedia , esta é uma forma abreviada para o Master of Arts:
A Master of Arts (M.A., MA, A.M., or AM) from the Latin Magister Artium, is a type of Master's degree awarded by universities in many countries.