Information with no reference in literature review
If you're confused about whether information comes from a citation, the clear solution is to go to the source being cited and look for it there.  

You will then find that one of two cases applies:


Yes, the information was in the source, and the citation was just confusing. Now you've read the source yourself and can cite it in a less confusing manner.
No, the information was not in the source, and you have no idea where it came from. Then the author either made a mistake or was dishonest. At this point, you either need to disregard the information as unreliable and unsourced or else try to contact the author to get a source.