Precovers and preenvelopes were introduced in the early eighties by Enochs [48] and,
independently, by Auslander and Smalø [16]. Enochs gave a general definition in terms of …

Precovers and preenvelopes were introduced in the early eighties by Enochs [48] and,
independently, by Auslander and Smalø [16]. Enochs gave a general definition in terms of …

Precovers and preenvelopes were introduced in the early eighties by Enochs [48] and,
independently, by Auslander and Smalø [16]. Enochs gave a general definition in terms of …