%0 Journal Article %T Assessment of Tropospheric Variation of Radio Refractivity and Field Strength Variability over Some Selected Stations in Northern Nigeria %J Journal Information: ISSN: Frequency: Journal DOI: Peer-review model: Digital Archiving: Disclaimer: Disclaimer: %D 2018 %R 10.9734/PSIJ/2018/41320 %X Editor(s): %U http://www.sciencedomain.org/abstract/24624