1. A method for detection of page numbers in a document comprising: identifying a plurality of text fragments associated with a plurality of pages of a single document; from the identified text fragments, identifying at least one sequence, each identified sequence comprising a plurality of terms, each term derived from a text fragment selected from the plurality text fragments, the terms of a sequence complying with at least one predefined numbering scheme which defines a form and an incremental state of the terms in a sequence, the at least one numbering scheme excluding terms from a sequence which do not comply with an incremental state in which terms on each two consecutive pages vary by a constant value, the identifying of the at least one sequence comprising, for each page of a plurality of pages of the document in sequence: identifying text fragments which comprise a term that complies with the form of the predefined numbering scheme; for each of the identified fragments, determining if the term of the identified fragment complies with an incremental state accepted by an existing sequence and if so, adding the term to that sequence, the existing sequence comprising at least one term derived from a text fragment of a previous page of the document; and for each of the terms which do not comply with an incremental state accepted by an existing sequence, considering the term as a potential start of a new sequence; with a computer processor, computing a subset of the identified sequences which cover at least some of the pages of the document, wherein the computing of the set of sequences comprises applying a Viterbi algorithm to the identified sequences to identify a subset of the identified sequences; and construing of at least some of the terms of the subset of the identified sequences as page numbers of pages of the document.