%0 Journal Article %T Progress and challenges of helical-shaped geothermal heat exchangers %A Rashidi, Saman %A Bakhshi, Naser %A Rafee, Roohollah %J Environmental Science and Pollution Research %V 28 %N 23 %P 28965-28992 %@ 0944-1344 %D 2021-04-16 %I Springer Berlin Heidelberg %~ DeepDyve