"gods" in Psalm 138

The "gods" in verse 1 of Psalm 138 likely refers to earthly rulers again, like I posted about regarding Psalm 82. Per the People's Bible: "The term 'gods' may refer to heathen gods, or, more rarely, to angels or even to earthly rulers. Since this psalm is David's invitation to the kings of the earth to join him in praising the true God, the rare meaning 'earthly rulers' is appropriate here. The NIV's use of quotation marks around 'gods' seems to indicate that the translators were adopting this interpretation of the term."