000			00331nam a2200157Ia 4500
008			190201s9999 xx 000 0 und d
020			_a9.78E+12
082			_a515
082			_b64 LAV
100			_aLavent`ev M.A.
245		0	_aVariational Methods
260			_aNew York
260			_bDover
260			_c1963
300			_a153
999			_c39921 _d39921