sentences:  Probably between the first and third sons were other apprentices and assistants whose identities are lost, though their work is sometimes clearly distinguishable.Andrea himself clearly sought to distinguish between the work of him and his family from that of other workers in his workshop by inserting labels saying "Sotto la disciplina" (Under the discipline of...).Andrea Guarneri was the first master to make this distinction; the Amatis never did this, though later Stradivari adopted this idea.