"What sefer are you learning?"

"That pshat is Reb Chaim in sefer." (Weiser)

"a tissue can also be put in the back of your Tallis bag, its miyus when they are left on the table or worse under a siddur or sefer that someone else will use later." (source)

"Would you like a second copy of a Sefer to keep at home instead of shlepping it to and from school daily?" (source)

"An incident with a Sefer Torah falling at the Ponovezh Yeshiva in Bnei Brak caused a great shock across the Torah world and led the roshei yeshiva to issue a detailed letter to the talmidim." (source)

"So what should we give him for his Bar Mitzvah, money or a sefer?" (Glinert)