Sources and causes

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Sources and causesSources and causesSources and causesSources and causesSources and causesSources and causes
Sources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causesSources and causes