Perhaps you should try some spelling variations:
upon conversations » union conversations, open conversations, spoken conversations
christianity upon » christianity among, christianity along, christianity from
reef history » brief history, reeves history, reef fishery
11th century » 18th century, 19th century, 17th century
2023 11th » 2023 5th, 2023 7th, 2023 8th
2 german » 3 german, 5 german