The clinical efficacy of Olibanum gum chewing in patients with Mild‐to‐Moderate Alzheimer disease: A randomized Parallel‐Design controlled trial oleh Fereshteh Ghorat, Mahdi Sepidarkish, Farzaneh Saadattalab, Maedeh Rezghi, Shamim Shahrestani, Maryam Gholamalizadeh, Saeid Doaei