major-thirds tuning
... that the Russian guitar's D-G-B-D-G-B-D tuning approximates the major-thirds tuning D#-G-B-D#-G-B-D#?
... that the <a href="./Russian_guitar" id="mwTg" rel="mw:WikiLink" title="Russian guitar">Russian guitar</a>'s D-G-B-D-G-B-D tuning <i id="mwTw">(illustrated)</i> approximates the <b id="mwUA"><a href="./Major_thirds_tuning" id="mwUQ" rel="mw:WikiLink" title="Major thirds tuning">major-thirds tuning</a></b> D#-G-B-D#-G-B-D#?