Muž na zamyšlenou tváři mezi hromadami knih v knihovně, regály na pozadí. Učitel nebo student s vousy nenosí brýle, sedí u stolu s knihami, rozostření. Vědecký výzkum koncept. - Stock fotografie a obrázky

Man on thoughtful face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific research concept.

Man on surprised face holds hourglass while studying, bookshelves on background. Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass.

Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass. Man on serious face watching time is going over, bookshelves on background.

Scientific discovery concept. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Man on shocked face between piles of books in library, bookshelves on background.

Man on nervous face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific discovery concept.

Teacher or student with beard sits at table with glasses, defocused. Man on strict face between piles of books, while studying in library, bookshelves on background. Bibliophile concept.

Time flow concept. Man on surprised face holds hourglass while studying, bookshelves on background. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass.

Man on happy face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific research concept.

Man on nervous face between piles of books in library, bookshelves on background. Scientific discovery concept. Teacher or student with beard wears eyeglasses, sits at table with books, defocused

Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific research concept. Man on thoughtful face between piles of books in library, bookshelves on background.

Time flow concept. Man on surprised face holds hourglass while studying, bookshelves on background. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass.

Time flow concept. Teacher or student with beard studying in library. Man, scientist in glasses looks at hourglass. Man on surprised face sits near hourglass while studying, bookshelves on background.

Scientific discovery concept. Man on excited face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused.

Teacher or student with beard sits at table with glasses, defocused. Man on strict face between piles of books, while studying in library, bookshelves on background. Bibliophile concept.

Scientific discovery concept. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Man on shocked face between piles of books in library, bookshelves on background.

Teacher or student with beard sit at table with hourglass and glasses, defocused. Bookworm concept. Man on shocked face sit between piles of books, while studying in library, bookshelves on background

Teacher or student with beard stands at table with books, defocused. Librarian concept. Man on thoughtful face stands between piles of books, while studying in library, bookshelves on background

Deadline concept. Teacher or student with beard sits at table making roof out of book, defocused. Man on shocked face between piles of books, while studying in library, bookshelves on background.

Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific discovery concept. Man on excited face between piles of books in library, bookshelves on background.

Man on nervous face between piles of books in library, bookshelves on background. Teacher or student with beard wears eyeglasses, sits at table with books, defocused. Scientific discovery concept.

Bibliophile concept. Teacher or student with beard sits at table with books, defocused. Man on hopeful face between piles of books, while studying in library, bookshelves on background.

Man on happy face between piles of books in library, bookshelves on background. Scientific research concept. Teacher or student with beard wears eyeglasses, sits at table with books, defocused.

Time flow concept. Man, scientist looks at hourglass. Teacher or student with beard studying in library. Man on serious and shocked face watching time is going over, bookshelves on background