"Personal and lightweight flammable gas monitors". Proceedings of the Analytical Division of the Chemical Society. 13 (4). Royal Society of Chemistry (RSC): 108. 1976. doi:10.1039/ad9761300108. ISSN0306-1396.
US Patent 3092799, Baker, Alan, "Apparatus for detecting combustible gases having an electrically conductive member enveloped in a refractory material"
"Personal and lightweight flammable gas monitors". Proceedings of the Analytical Division of the Chemical Society. 13 (4). Royal Society of Chemistry (RSC): 108. 1976. doi:10.1039/ad9761300108. ISSN0306-1396.