Coherent emissions are produced by plasma waves, which are usually caused by non-thermal electrons or ions (beams, currents, shocks, magnetic traps).
		Problems: 1.  Role in flare phase and geometry unclear    (Pulsations: preflare, flare, postflare?)
		3. No confirmations by observations!
	Eidgenössische Technische Hochschule Zürich Swiss Federal Institute of Technology,  Zürich