For further information on P. L. Robertson, please see "P. L. Inventor of the Robertson Screw" by Ken Lamb and "Milton Area Biographies" by Alex Cooke.
For further information on P. L. Robertson, please see "P. L. Inventor …
For further information regarding P.L. Robertson, please consult "P.L. Inventor of the Robertson Screw" by Ken Lamb, and "Milton Area Biographies V.2."
For further information regarding P.L. Robertson, please consult "P.L. Inventor of the …
Peter Lymburner Robertson, 1879-1951. Inventor, industrialist. Inventor of the Robertson Recess Screw. For more information, see "P. L. Inventor of the Robertson Screw" by Ken Lamb.
Peter Lymburner Robertson, 1879-1951. Inventor, industrialist. Inventor of the Robertson Recess Screw. …