Analysis of information sources in references of the Wikipedia article "Elective monarchy" in English language version.
The Pskov men invited princes to Pskov whose professional armoured cavalry was very important for a city that had constant wars with the Livonian Order. [...] The princely power grew during the fourteenth and fifteenth centuries while the prince himself usually was a protégé of the grand prince of Moscow. [...] However, the right that was especially valued by Pskov men was that to expel princes whom they disliked.
From 1075 the people of Novgorod 'invited' the prince to take the throne and it is clear that the princes were now there only so long as they satisfied the Novgorodians and obeyed their laws.
On the Novgorod and Pskov communities' practice of inviting princes from the Grand Duchy of Lithuania, see Anna Khoroshkevich, 'Istoricheskie sud'by belorusskikh i ukrainskikh zemel' v XIV – nachale XVI v.,' in Vladimir Pashuto, Boris Floria, and Khoroshkevich, Drevnerusskoe nasledia i istoricheskie sud'by vostochnogo slavianstva (Moscow, 1982), pp. 140–141.
If there was no uparaja at the time of the king's death—and this was frequently the case—the choice of a new monarch drawn from the royal family was left to the Senabodi, the council of senior officials, princes, and Buddhist prelates that assembled at the death of a king. It was such a council that chose Nang Klao's successor.
On the Novgorod and Pskov communities' practice of inviting princes from the Grand Duchy of Lithuania, see Anna Khoroshkevich, 'Istoricheskie sud'by belorusskikh i ukrainskikh zemel' v XIV – nachale XVI v.,' in Vladimir Pashuto, Boris Floria, and Khoroshkevich, Drevnerusskoe nasledia i istoricheskie sud'by vostochnogo slavianstva (Moscow, 1982), pp. 140–141.