How to find obituary/death info in Ostrava from 1960-1975

Hello, I am trying to find the exact death date of Josef Lanik (b.Nov 14, 1879 in Frycovice) who died in Ostrava sometime between 1960-1975. He was Catholic and is buried in the Marianske Hory cemetery. I contacted the cemetery and they tell me that their “book” for that time frame is missing. ??? Is there some other way to get his exact death date? He was married to Maria Smirak. He was a miner. Any info would be appreciated. Thank you in advance.