They learned how to preach using literature and testimony cards, as well as phonograph recordings in English, German, Hungarian, Polish, Spanish and, later, Portuguese.
Mereka belajar cara menginjil dengan menggunakan bacaan, kartu kesaksian, serta rekaman khotbah dalam bahasa Hungaria, Inggris, Jerman, Polandia, Spanyol, dan belakangan, Portugis.