Pollard, A., & Clarke, C. (1988). Deaths during mountaineering at extreme altitude.
Chicago-viite (17. p.)Pollard, A., ja C. Clarke. Deaths During Mountaineering at Extreme Altitude. 1988.
MLA-viite (9. p.)Pollard, A., ja C. Clarke. Deaths During Mountaineering at Extreme Altitude. 1988.
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