This is the 8016th most frequent Russian word.
кравчука
"Кравчука" is not a standard Russian word; it may refer to a surname (Kravchuk) or require additional context for specific meaning.
Here 'кравчука' refers to Kravchuk, possibly the author or creator of the book, implying possession or attribution.
Он купил книгу кравчука.
He bought the book by Kravchuk.
In this context, 'Кравчука' is used to indicate the namesake person for whom the museum is named, showing genitive case usage.
Мы посетили музей имени Кравчука.
We visited the museum named after Kravchuk.
Here 'Кравчука' indicates possession, showing that the idea belonged to Kravchuk, using the genitive case.