The field of the Patristic studies and publications has showing a great expansion inside a lot of sites and groups, where the themes involved such oriental studies, lexicographic and bibliographic research, inclusive other aspects like the indexation of big quantities of text are the subjects and tools for a daily work.
Doesn’t enough to know where some contents directly can be founded, some sites, i. e. the Google Books Project, adds day to day until 10,000 volumes, making in some cases almost impossible to find any content in a preliminary search.
The ‘keywords’ are the most common way to search in the sites, but some books changes their title between edition and place of print.
Is very useful to have an extended quantity of translations for the same word, in our situation, Arameo [for spanish], Aramaic [for english], Arämaisch [for german], Aramaico [for portuguese].
The wrong writting of any word must be a frequent factor to exclude in any search some volumes what are effectively inside some sites. You can test this, making a search in Internet Archive with the Aramäisch word without the overpuncted ‘ä’: the word aramaisch does not show any result.
The name of the authors, in a few cases, change its orthography leaving out some specific special letters, to make they accessible and searchable between the search automated motors. If the author you are looking for has in his name a non-latin letter, try to convert it to the most close written character possible, i. e.: ç to c, æ to ae.
The most common format to work and publish and digitize books, papers and essays, is the PDF [Portable Document Format]. This format works well and fine with a ‘medium’ size book, think in a 250-350 pages book. If the book was edited and published digitally, the size of the whole volume can have only a pair of megabytes. But in the old books digitized with opto-mechanical methods, the size of a medium book must have 34-50 megas -talking about any book inside Internet Archive- if the pages maintain the color profiles; the same book, in Google Books Project will have a smallest size: the color profiles for all the books in Google Books are excluded, and the images are binded in b/w.
The .doc or .txt is very unusual, but other graphic formats are used to make the digitizations, not only .jpg or .gif.
If the site shows .tif or .tiff images, almost all the OS have an image viewer to this filetype. Some sites offer the original images obtained with the scanners, but the use of some plugin or specific viewer in this cases must be required.
A good idea is to install some advanced image editor, overall if you have the idea to print the images for personal study. Photoshop, ACDsee, or GIMP can deal with the most raw format images.
InternetArchive, Googlebooks, BYU [www.lib.byu.edu/dlib/cua/], RELTECH [http://alpha.reltech.org/]… and ‘course: This blog!