Crossword clues for Source of 20 Across 4 lettersAnswerClueATOMSource of 20 AcrossBODYWith 20-Across, natural energy sourceBILLYGOATReputed source of the 1-Across for 20-AcrossSONJAWith 71-Across, former skater/film star, and the source of the quote starting at 20-AcrossCHARLESDICKENSSource of 20 AcrossTATERFolksy starch source found in 20-, 37- and 49-AcrossSILENTPARTNERBehind-the-scenes money source ... and a hint to the start of 20-, 35- and 43-AcrossEDGERSLawn trimming tools (Bonus diagonal clue: Extra power source, literally? [enter from this answer's 3rd letter to 20-Across' 4th letter])