Quote the exact text that specifies this.
“The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence”
The fact that you believe “masks and respirators” in the title of the document you linked to refers to dust masks and pieces of cloth fastened over your face and not PPE (personal protective equipment) used by health-care professionals is laughable to begin with.
“influenza” is in the title as well... you would never refer to the current form of novel coronavirus as the flu would you? That won't make the merry little band of fearpers here happy. Don't you realize that your “expert” leadership believes this as “easy to catch as the common cold” but has a “7% death rate”. Come on man what are you thinking?
“The initial review was performed in November 2009 and updated in June 2010 and January 2011.”
Kind of speaks for itself.
“Six of eight randomised controlled trials found no significant differences between control and intervention groups (masks with or without hand hygiene; N95/P2 respirators).”
Somehow they mention “N95/P2 respirators” but not dust masks and pieces of cloth worn over your face. This is in the second paragraph of the abstract at the very beginning of the link you provided. You are wasting everyones time here when you don't even bother to read the second paragraph found at the link that you provided.