See the link:

http://lexicon.ft.com/Term?term=m0,-m1,-m2,-m3,-m4

The answer to your question depends on the region/country for which you want to conduct the research. Usually, start with the definition of the monetary aggregates provided by central bank of the respective country or the regional monetary authority.

E.g. see: https://www.ecb.europa.eu/pub/pdf/other/mb199901_focus02.en.pdf?0fcb25a70f7f6f010a66ec2be8eea07a

https://www.ecb.europa.eu/pub/pdf/other/ebbox201706_07.en.pdf?0f61cf60e8a74e89e5718dcbce77a818

Thank you Cornelia Pop.