By Portnyagin D.   in Ukrainian Mathematical Journal

ISSN:0041-5995|58|8|1223-1237

Springer Publishing Company ‎(2006)‎

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By Portnyagin D.   in Journal of Mathematical Sciences

ISSN:1072-3374|170|5|604-611

Springer Publishing Company ‎(2010)‎

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By Portnyagin D.   in Differential Equations

ISSN:0012-2661|47|4|593-598

MAIK Nauka/Interperiodica‎(2011)‎

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By Portnyagin D.   in Differential Equations

ISSN:0012-2661|46|6|896-900

MAIK Nauka/Interperiodica‎(2010)‎

Access to resources Favorite 15.66578