Michel, Philippe2008-11-142008-11-142008-11-14199810.1215/S0012-7094-98-09507-2https://infoscience.epfl.ch/handle/20.500.14299/30945complete exponential sumsalmost prime moduluslower boundpositive densitymultidimensional Kloosterman sumLower bounds of exponential sums. (Minorations de sommes d'exponentielles.)text::journal::journal article::research article