This article is not complete - please help by providing the missing QTH info! Also, any QSL scans for callsigns that do not have a blue link would be appreciated.

DXNS #786, dated 1977-10-25 reports that the USSR-Poland Friendship Week took place in October, 1977. 
Very little information is available about this event, but the following stations are known to have been active. Operational dates appear to have been 17-23 October. All stations were operated by clubs.

Callsign DXCC City Note Comment
U1USP European Russia Leningrad QSL via UK1AAA (DXNS #788) UK1AAA = a club station in oblast 169, UA1A
U2USP Lithuania     QTH required - Appears to have been operated by the LY2ZZ Contesting/DX Club
U3USP European Russia Moscow   Confirmation of QTH required
U4USP European Russia     QTH required
U5USP Ukraine Rovno QSL via UK5KIZ (DXNS #817) UK5KIZ = club station in oblast 072, UB5K
U6USP European Russia     QTH required
U7USP Kazakhstan     QTH required
U8USP Uzbekistan Tashkent QSL via UK8AAI (DXNS #817) UK8AAI = a club station in oblast 053, UI8A
U9USP Asiatic Russia Omsk QSL via UK9MAA (DXNS #788) UK9MAA = a club station in oblast 146, UA9M
U0USP Asiatic Russia     No evidence that U0USP was QRV