McMahon, Glenda Chatterton, Ken Sanitary seal for a borehole Sanitary seal for a borehole WEDC;Sanitary seals;Santitation;Technical;Diagram;Borehole;Handpump;International and Development Communication 2019-04-30
    https://repository.lboro.ac.uk/articles/figure/Sanitary_seal_for_a_borehole/7982648
10.17028/rd.lboro.7982648.v1