QUES: What could be reasons for these differences

correct the punctuation.

CORRECTED: What could be reasons for these differences?

QUES: Agricultural tractors and forestry tractors wheeled new of an engine power 90 kW excl tractor units for articulated lorries

correct the punctuation.

CORRECTED: Agricultural tractors and forestry tractors, wheeled, new, of an engine power > 90 kW (excl. tractor units for articulated lorries)

QUES: For details please refer to the installation manual for your architecture especially the chapter Obtaining System Installation Media

correct the punctuation.

CORRECTED:
For details, please refer to the installation manual for your architecture, especially the chapter Obtaining System Installation Media.