BibSlavKon: 4 hits for Velčev, V.

The Bibliography of International Congresses of Slavists (1929-2018) was converted from thirteen printed volumes into a database in cooperation with the Slavonic Library in Prague (Slovanská knihovna Praha) and contains 8550 records. Since 2008 the Bibliography appear only in electronic form and will be updated in five-year interval according to the next Congresses of Slavists. The further information can be found here. The overview of the classification can be found: here.

Your search for Velčev, V. provides 4 hits
1	I. S. Turgenev i bălgarskata kultura Velčev, V. - Slavjanska filologija (1983), 97-112
2	Tvorčeskijat metod na Chr. Botev i tradiciite na romantizma i realizma Velčev, V. - Slavjanska filologija (1973), 155-179
3	Tragedija gordogo iskanija poznanija, svobody i tvorčestva : (k voprosu ob idejnoj problematike poemy M. Ju. Lermontova „Demon“) Velčev, V. - Slavjanska filologija : materiali za V Meždunaroden kongres na slavistite (1963), 121-148
4	Văzdejstvieto na ruskata klasičeska literatura za formirane i razvitie na bălgarskata literatura prez XIX vek : (kăm văprosa za bălgaro-ruskite literaturni vrăzki do Osvoboždenieto) Velčev, V. - 1958, 115 s.

Bibliography of International Congresses of Slavists (BibSlavKon)

I. S. Turgenev i bălgarskata kultura

Tvorčeskijat metod na Chr. Botev i tradiciite na romantizma i realizma

Tragedija gordogo iskanija poznanija, svobody i tvorčestva : (k voprosu ob idejnoj problematike poemy M. Ju. Lermontova „Demon“)

Văzdejstvieto na ruskata klasičeska literatura za formirane i razvitie na bălgarskata literatura prez XIX vek : (kăm văprosa za bălgaro-ruskite literaturni vrăzki do Osvoboždenieto)