− | *Gay ML, Musser SM. Single-laboratory validated method for determination of nordihydroguaiaretic acid in chaparral-containing dietary supplements. J AOAC Int. 2008 May-Jun;91(3):501-5. | + | *Gay ML, Musser SM. Single-laboratory validated method for determination of nordihydroguaiaretic acid in chaparral-containing dietary supplements. J AOAC Int. 2008 May-Jun;91(3):501-5. |