Design of Special Planar Linkages / J. Zhao [et al.], 2014 r=on-line. - Текст : электронный.
Andreescu T. 104 number theory problems : from the training of the USA IMO team / T. Andreescu, D. Andrica, Z. Feng, 2007 r=on-line. - Текст : электронный.
Andreescu T. 103 trigonometry problems : from the training of the USA IMO team / T. Andreescu, Z. Feng, 2005 r=on-line