Studies composed by

Ljubomir Ugren

(Slovenia, 1.1.1940  Bosnia and Hercegovina)

At slovenia Wikipedia we can read about his (chess) career which is impressive.

A bit of translation to english:

From 1969 to 1971 he worked as the Secretary of the Chess Federation of Slovenia, and from 1972 until the retirement in 2005 at the Statistical Office of the Republic of Slovenia.
For more than 20 years, he was chairman of the Committee for Problem Chess ŠZS and member of the Council of Problems Chess of the Chess Federation of Yugoslavia, and from 1987 to 1989 his president.

So far, he has published more than 400 original chess problems of all genres and studies, about half of which are featured in tournaments at home and abroad.

There are eleven problems published in FIDE Albums. He is also one of the few assemblies of studies with us.

He has created several world record records. He was the national champion of Yugoslavia in the 1985 compilation.

In the 1993-96 World Championship, he shared the 5th and 6th place in the compilation of original themed auxiliary mat.
Ugren has the title of the Yugoslav chess master of the problem and is the international judge of the Commission for Problem Chess at the international chess organization FIDE.

He is an International Judge for chesscomposition since 1977.

(All his studies, more exact dates, possible corrections or cooks and exact details about sources can be found in the

Harold van der Heijden database V (31-12-2015) )