APA

Gray E., . (1999). Jorney to the Centre of the Earth. Swansea: Express Publishing.

Chicago

Gray E, . 1999. Jorney to the Centre of the Earth. Swansea: Express Publishing.

Harvard

Gray E., . (1999). Jorney to the Centre of the Earth. Swansea: Express Publishing.

MLA

Gray E, . Jorney to the Centre of the Earth. Swansea: Express Publishing. 1999.