Template:Jarvis-DSW
Jarvis, Peter (1994) [1993]. Adeiladu muriau cerrig sych ar Reilffordd Ffestiniog = Dry stone walling on the Ffestiniog Railway. Porthmadog: Rheilffordd Ffestiniog Railway. ISBN 0901848077. OCLC 30157087.
Jarvis, Peter (1994) [1993]. Adeiladu muriau cerrig sych ar Reilffordd Ffestiniog = Dry stone walling on the Ffestiniog Railway. Porthmadog: Rheilffordd Ffestiniog Railway. ISBN 0901848077. OCLC 30157087.