1991 Sino-Russian border agreement
...that the terms of the 1991 Sino-Russian border agreement between the Russian Federation and the People's Republic of China took over 6 years to implement?
...that the terms of the <b id="mwAV0"><a class="mw-redirect" href="./1991_Sino-Russian_border_agreement" id="mwAV4" rel="mw:WikiLink" title="1991 Sino-Russian border agreement">1991 Sino-Russian border agreement</a></b> between the <a class="mw-redirect" href="./Russian_Federation" id="mwAV8" rel="mw:WikiLink" title="Russian Federation">Russian Federation</a> and the <a class="mw-redirect" href="./People's_Republic_of_China" id="mwAWA" rel="mw:WikiLink" title="People's Republic of China">People's Republic of China</a> took over 6 years to implement?