Columbia subject headings:
English language--Dictionaries--Russian.
Environmental protection--Dictionaries--Russian.
Environmental protection--Dictionaries.
Russian language--Dictionaries--English.
Harvard subject headings:
English language--Dictionaries--Russian
Environmental protection--Dictionaries
Environmental protection--Dictionaries--Russian
Russian language--Dictionaries--English.
Princeton subject headings:
Dictionaries.
English language--Dictionaries--Russian.
Environmental protection--Dictionaries--Russian.
Environmental protection--Dictionaries.
Russian language--Dictionaries--English.