APA (7th ed.) Citation
Eckersley, C. (1967). Essential English for Foreign Students: Book four. Foreign Languages Press.
Chicago Style (17th ed.) Citation
Eckersley, C.E. Essential English for Foreign Students: Book Four. Sofia: Foreign Languages Press, 1967.
MLA (9th ed.) Citation
Eckersley, C.E. Essential English for Foreign Students: Book Four. Foreign Languages Press, 1967.
Warning: These citations may not always be 100% accurate.