Elementary Number Theory with Applications szerző: Thomas Koshy http://books.google.ro/books?id=-9pg-4Pa19IC&pg=PA287&lpg=PA287&dq=system+of+linear+congruences&source=bl&ots=ArXPKsvDqW&sig=_xNCanaXwDBs_C0mCdvMeMu4BOw&hl=hu&sa=X&oi=book_result&resnum=10&ct=result#PPA316,M1