RESERV The Versalog Slide Rule Instruction Manual (Fiesenheiser, 1951) DIR The Slide Rule - A Complete Manual (Slater, 1967) RESERV The Use of the Slide Rule (Cullimore, 1920) RESERV The Handbook of the Slide Rule (Bayley, 1876) whitemesa.net:70 /slide-rules:5: invalid line / field count