1 Subjects: “...physical activity, low back pain, older adults, health outcomes, exercise, wearables...”

2 Subjects: “...Focus on 18th and 19th century with reference going back to 1215...”

3 Subjects: “... Paralyzed by Pillages and War;IPPF;The 2000s: Family Planning – Like the Country – Inches Back to Normalcy...”

4 Subjects: “...back-propagation neural network...”