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		| Paper: | 
		Spectroscopy of BL Lac Objects:  New Redshifts and Mis-identified Sources | 
	 
	
		| Volume: | 
		299, High Energy Blazar Astronomy | 
	 
	
		| Page: | 
		299 | 
	 
	
		| Authors: | 
		Carangelo, N.; Falomo, R.; Kotilainen, J.; Treves, A.; Ulrich, M.-H. | 
	 
	
	
		| Abstract: | 
		We are carrying out a program of high signal to noise optical spectroscopy of BL Lacs with unknown or tentative redshift. Here we report some preliminary results. New redshifts are measured for PKS0754+100 (z=0.266) and 1ES0715-259 (z=0.464). From lineless spectra of PG1553+113 and PKS1722+119 we set a lower limit of z>0.3 for both sources. In two cases (UM493 and 1620+103) stellar spectra indicate a wrong classification. | 
	 
	
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