Air combat on 25.2. 1945

Hello,
For the start I say some short story.
On the 25.februar 1945 was offensive of red army in the direction Detva – Zvolen – Banska Bystrica(In Slovakia – that time Czechoslovakia). Around 14:00h took off two romanian pilots from airfield in Lucenec – adjutant Traian Darjan and capitan Constantin Cantacuzino (They were from 9.fighter group of ARR.). Over Zvolen they found german Fw 190s which were attacking soviet infantry. Constantin Cantacuzino downed one of them. Pilot of machine was gefreiter Hermann Heim from I./SG 2. When they were finding wreck of Fw 190 to confirm vyctory, they lost carefulness and were attacked by german Bf 109s. First downed pilot was Traian Darjan who was victim of german ace from JG 53 Hauptmann Helmut Lipfert. Then was downed Cantacuzino too, but by unknown german pilot.
My questions:
Who downed Cantacuzino?
Where can I find some biographical informations about Hermann Heim?
Where I can found some mission reports from that days?
My last request: If you got any informations, web-sites, books, forums, pictures, photographs, memoirs, contacts or anything other what could help me, please post it here or send there: detvan1945@gmail.com . To pictures or photos I need sources or contact to owners if it is possible.
I will be thankful for any answer.

[Black6]

Nachname: Heim
Vorname: Hermann
Dienstgrad: Flugzeugführer
Geburtsdatum: 02.10.1924
Geburtsort: Aalen
Todes-/Vermisstendatum: 25.02.1945
Todes-/Vermisstenort: 3 km n. Slatina

[Black6]

Lipfert claimed a Yak-9 at Zvolen at 10:53 that day, possibly the other victor was Oblt Hans Kornatz also of JG53 ?

[HGabor]

On February 25, 1945 Hptm. Lipfert downed probably one of the two lost Yak-9 fighters of 5 VA, 331 IAD, 513 IAP while escorting 6 451 ShAP IL-2s to Plesovci. Dogfight at 2000 m, 2 Yaks were lost out of 6 in Zvolen-S area near Szuhány (Sucháň). The IL-2s suffered no losses.

ст.л-т Рыбалко Андрей Антонович was downed in dogfight in Yak-9T, S/N: 2015385,
мл.л-т Ананьев Алексей Гаврилович was downed in dogfight in Yak-9M, S/N: 2615337.

Gabor
(Having photo of both pilots.)

[Alfred.MONZAT]

Dénes Bernád wrote an article on Constantin « Bâzu » Cantacuzino in Avions n°209/210. He details this combat from both point of view with accounts from the (supposed) victor. I think the victor was Helmut Lipfert and he identified his victim as romanian, but someone with the magazin on hands (or the author himself) may confirm/infirm that.

Thank you,
I know about fight with Yaks, but I need informations about fight with these romanian pilots.
So who downed Cantacuzino? It could be Hans Kornatz, but there was other aerial combat between ARR and LW after this, which he participated too.
Exist some list with pilots of I./JG53 who flew this day?
Have somebody that magazine(Avions n°209/210)?
Some longer biography of Hermann Heim(where did you get it)?
Thank you a lot.