Since Czech Republic indeed is the "bridge between east and west" and has a huge number of experts on russian military technology, we're well positioned to analyze developments in Doneck and Luhansk area of Ukraine.
So, since the world media doesn't seem to have noticed and instead relies on public not-proof-of-anything sattelite imaginery, I decided I would share here recent photos proving that Russia indeniably is sending tanks to the Ukraine, because they have deployed at lest one BTR-82A (IOC in russian army 2013) and at least two T-72B3 (IOC in russian army 2013):

(Also, see
video of the same vehicle, crewed presumably by Osetians pretending to be Chechens,
difference between ukraine and russian variants of BTR and finally, proof that the separatist's BTR is
not BTR-80, but BTR-82A instead due to presence of the TKN-4GA thermal sight)
The moset obvious difference between T-72B, which the separatists could have taken from Ukraine, and T-72B3, which is world-exclusive to the Russian Army, is the thermal sight / missile guidiance system Sosna-U which has replaced the old 1K13.
The destroyed turret of T-72B3 is laying on Ukraine on the fighting ground below Ilovajsk; Ukraine has captured one, separatists/Russians were fighting with the other one, both were destroyed.

Be advised that the russian Secretary of Defense, Sergei Shoigu, has converted the russian army into quite combat-worthy force by doing real surprise checks on various bases -- checks about he didn't tell anyone but his driver/pilot, so the bases didn't have time to prepare for inspection -- and thus made all first line units
constantly combat-ready. It is therefore absolutely impossible that the elite 20th guards armored brigade "lost" one of their new T-72B3s without anyone noticing -- that is no longer possible.