The free pdf's of the book in English can be found below:
Wally and Deannas Groundwater Adventure (English)
The pdf's of translations are below in alphabetical order based on translation language in English:
Afrikaans translation by Fanus Fourie
Willie en Deidré se Grondwater Avontuur (Afrikaans)
Arabic translation by Yasamen Abdulbasit Alahmar and Hind Bash Imam, Scientific and linguistic review by Khalil Ibrahim Al-Samarrai
مغامرات والي وديانا في المياه الجوفية (Arabic)
Creole translation by Sabine Cherenfant
Janjan ak Dayana Al Wè Dlo Anba Tè (Creole)
French translation by Paisley Worthington
Vic et Gabrielle explorent les eaux souterraines (French)
German translation by Christina Formanek
Willi und Tinas abenteuerliche Grundwasser-Reise (German)
Greek translation by Ειρήνη Νταγκουνάκη
Η ΠΕΡΙΠΕΤΕΙΑ ΤΟΥ ΝΙΚΟΛΑ ΚΑΙ ΤΗΣ ΝΕΡΟΣΤΑΛΙΤΣΑΣ ΣΤΑ ΥΠΟΓΕΙΑ ΝΕΡΑ (Greek)
Hausa translation by Aminu Ibrahim
Tafiyar ƙoƙi da gizo don ganin ruwan ƙasa (Hausa)
Hungarian translation by Judit Déri-Takács
Kristóf és Csilla vízi kalandjai (Hungarian)
Indonesian translation by Azwar S. Muhammad
Cata dan Tesa Petualangan Air Tanah (Indonesian)
Italian translation by Eleonora Lupi and Mara Meggiorin
L’avventura nelle acque sotterra- nee di Wally e Dina (Italian)
Japanese translation by Kimpei Ichiyanagi
ウォーリーとディアンナの 地下水アドベンチャー(Japanese)
Malay translation by Intan Saimy
Pengembaraan Air Tanah Adi dan Dina (Malay)
Mandarin translation by YingYing Liu
Portuguese translation by Nilson Guiguer and Elaine Azevedo
Aventuras de Léo e Bia pelas Águas Subterrâneas (Portuguese)
Spanish translation by Luis Camilo Suescún
La aventura en las aguas subterráneas de Diego y Sara (Spanish)
Urdu translation by Muqaddas Tariq
چنکو-اور-مینا-کی-مہم-جوئی (Urdu)
Yoruba translation by Dr. Oluwole Ayinde Oyedeji
Irin ajo Juli ati Ola lo si inu ile nibi ti omi ti nsun (Yoruba)