Which sources – physical, oral or written – are more important? Why did you decide so?

It seems to me that the most important are material sources. Oral sources can be interpreted in different ways by people, and after a while their content may be distorted. This is not to say that written sources are absolutely reliable: the language that was used to create them may become outdated and no longer used.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.