Teacher's hand writing complicated mathematical formulas on the whiteboard 0Archiv

Teaching writing and explaining the discriminant Formula in quadratic equations 0Archiv

Young scientist standing over chalkboard filled with different scientific formulas 0Archiv

Old German intercom system at the entrance to 11 stories building 0Archiv

Nadir Divan-begi Madrasah, Bukhara, Uzbekistan 0Archiv

Lyab-i Hauz Ensemble. Also spelled Lyab-i Khauz, Lyabi Hauz, Lyabi Khauz. The most popular Bukhara tourist attraction 0Archiv

Kalyan Minaret of Bukhara, located in Po-i-Kalyan mosque complex in Bukhara, Uzbekistan 0Archiv

The Mir-i-arab Madrassah seen beyond the doors of the Kalon Mosque, Bukhara, Uzbekistan 0Archiv

Adult vitamins isolated on white background 0Archiv

Path along the sport complex / Weg entlang des Sportkomplex 0Archiv

Classical Portugese Lighthouse at dawn 0Archiv