def std_ref_form(ref_string):
    """
    Deletes unnecessary chars from the string.
    Seperates combined references.
    returns the refernces in a list.
    """
    if ' corr.' in ref_string:
        ref_string = ref_string.replace(' corr.','')
    
    while ',' in ref_string:
        ref_string = ref_string.replace(', ',']#[')
    
    refs_list = ref_string.split('#')
    return refs_list