 sdi some econom organiz aspect in context symposium appropri deal econom aspect select dissemin inform sdi oper in opinion technic feasibl merit sdi adequ demonstr main barrier hinder gener tend econom natur at shell research sittingbourn oper 1967 sdi servic staff grown rapidli start ca condens tape earli 1969 in addit tape current ba preview tape agdoc tape prepar punch card input receiv derwent experiment basi toxitap produc biosi philadelphia all tape search local involv run profil weekli 