She talked about them more in The Objectivist Newsletter , The Objectivist , The Ayn Rand Letter , Introduction to Objectivist Epistemology and The Virtue of Selfishness . She further elaborated on them in her magazines The Objectivist Newsletter , The Objectivist , and The Ayn Rand Letter , and in non-fiction books such as Introduction to Objectivist Epistemology and The Virtue of Selfishness .