Reference to information that is retrievable is appropriately made in the reference list. This includes but is not limited to articles published or accepted for publication in scholarly or mass-circulation print or electronic journals, magazines, or newspapers; books that have been published or accepted for publication; papers presented at professional meetings; abstracts; theses; CD-ROMs, films, videotapes, and audiofiles; package inserts or a manufacturer’s documentation; monographs; official reports; databases and websites; legal cases; patents; and news releases.
References should be listed in numerical order at the end of the manuscript (except as specified in 3.3, References Given in Text, and 3.5, Numbering). Two references should not be combined under a single reference number.
References to material not yet accepted for publication or to personal communications (oral, written, and electronic) are not acceptable as listed references and instead should be included parenthetically in the text (see 3.3, References Given in Text; 3.15, Electronic References; and 3.13.8, Special Print Materials, Unpublished Material).