P. Hrnciar

Michael addition of 1,3-cyclopentanedione, 1,3-cyclohexanedione and 1,3-cycloheptanedione to 1-(X-phenyl)-2-nitroethylenes

P. Hrnčiar, I. Čulák, P. Hrnciar, 1984 .

All trees of diameter five are graceful

Pavel Hrnciar, Alfonz Haviar, Alfonz Haviar, 2001, Discret. Math..