Natan Solomonovich Belenʹkiĭ

• Sbornik zadach i uprazhneniĭ po khozi︠a︡ĭstvennym vychislenii︠a︡m
• Schetnye tablit︠s︡y dli︠a︡ khozi︠a︡ĭstvennykh vychisleniĭ
• Tablit︠s︡y obratnykh chisel