“…To a certain extent, however, most of these difficulties could be corrected for, and thanks in part to the redundancy in energy coverage between the instruments a moderately coherent picture of the inner zone intensities has emerged. (For primary reports on the Pioneer observations, see the work of Fillius and Mcllwain [1974a, b], Fillius et al [1975], Fillius [ 1976], Simpson et al [ 1974aSimpson et al [ , b, 1975, Simpson and McKibben [1976], Trainor et al [1974aTrainor et al [ , b, 1975, McDon-aM and Trainor [ 1976], Van Allen et al [ 1974a, b, 1975], Van Allen [1976, 1977], and Van Allen [1976]. )…”