"The use of air photography in Celtic field studies", P. Harder Sørensen, "Journal of danish Archaeology" t. 1 (1982), s. 77-86 : [recenzja]

Archeologia Polski, Tom 31, Numer 1 (1986) s. 217-221
Iwona Modrzewska-Marciniak , P. Harder Sørensen (aut. dzieła rec.)