J. M. Petzval (1807-1891), J. Strouhal (1850-1922) and V. Ja (Czechoslovakia 1987)

06 July (Czechoslovakia ) within release Anniversary goes into circulation Stamp J. M. Petzval (1807-1891), J. Strouhal (1850-1922) and V. Ja face value 50 Czechoslovak haléř

Stamp J. M. Petzval (1807-1891), J. Strouhal (1850-1922) and V. Ja in catalogues
Michel:	Mi:CS 2920
Yvert et Tellier:	Yt:CS 2731
POFIS:	POF:CS 2803

Stamp is square format.

Also in the issue Anniversary:

• Stamp - Prague Town Hall mathematical clock, Theory of Functions dia face value 50;
• Stamp - Geographical measurement (1672), Earth fold and Brownian mot face value 50;
• Stamp - J. M. Petzval (1807-1891), J. Strouhal (1850-1922) and V. Ja face value 50;