@conference {OA2008,
	title = {High Efficiency Resonant Power Conversion},
	booktitle = {1st USSR Conference (with international participation) of Power Electronics Systems and Low?Power Converters Equipment (SES i UMPT)},
	year = {1990},
	url = {http://oa.uninova.pt/2008/},
	author = {Stanimir Valtchev and J. Ben Klaassens}
}
